Terminal device, integrated circuit, and wireless communication method

ABSTRACT

There is provided a terminal device that transmits a signal to a base station apparatus through uplink, the terminal device including: a transmission unit that transmits to the base station apparatus a first MAC control element which includes a first buffer size field indicating an amount of first data available for transmission within a first buffer for the uplink and a second MAC control element which includes a second buffer size field indicating an amount of second data available for transmission within a second buffer for a first link that is used for communication between the terminal device and a different terminal device, in which, in a case where a first parameter is not configured, a value that is used in the first buffer size field is indicated with a first table, in which, in the case where the first parameter is configured, the value that is used in the first buffer size field is indicated with a second table, and in which a value that is used in the second buffer size field is indicated at all times with the first table.

TECHNICAL FIELD

The present invention relates to a terminal device, an integratedcircuit, and a wireless communication method.

This application claims the benefit of Japanese Priority PatentApplication No. 2014-058182 filed on Mar. 20, 2014, the entire contentsof which are incorporated herein by reference.

BACKGROUND ART

In the 3rd Generation Partnership Project (3GPP), a radio access scheme(Evolved Universal Terrestrial Radio Access (EUTRA)) and a radio accessnetwork (Evolved Universal Terrestrial Radio Access Network (EUTRAN))for cellular mobile communication have been considered. EUTRA and EUTRANare also referred to as Long-Term Evolution (LTE). In LTE, a basestation apparatus is also referred to as an evolved NodeB (eNodeB) and aterminal device is also referred to as a User Equipment (UE). LTE is acellular communication system in which an area is divided in a cellularpattern into multiple cells, each being served by a base stationapparatus. A single base station apparatus may manage multiple cells.

In 3GPP, Proximity Services (ProSe) have been considered. ProSe includesProSe discovery and ProSe communication. The ProSe discovery is aprocess that, using EUTRA, specifies that a terminal device is inproximity to a different terminal device. The ProSe communication iscommunication between two terminal devices that are in proximity to eachother using a EUTRAN communication path that is established between thetwo terminals. For example, the communication path may be establisheddirectly between the terminal devices.

The ProSe discovery and the ProSe communication are also referred to asD2D discovery and D2D communication, respectively. The D2D discovery andthe D2D communication are collectively also referred to as D2D.

In NPL 1, it is disclosed that a subset of resource blocks is reservedfor the D2D, that a network configures a set of D2D resources, and thatthe terminal device is allowed to transmit a D2D signal using theconfigured resources.

CITATION LIST Non Patent Literature

-   NPL 1: “D2D for LTE Proximity Services: Overview”, R1-132028, 3GPP    TSG-RAN WG1 Meeting #73, 20-24 May 2013.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

An object of the present invention, which was made in view of thesituation described above, is to provide a terminal device, anintegrated circuit that is built into the terminal device, and awireless communication method that is used in the terminal device, inall of which processing associated with a Buffer Status Report (BSR) ora Scheduling Request (SR) can be efficiently performed.

Means for Solving the Problems

(1) In order to accomplish the object described, the following means arecontrived according to the present invention. That is, according to anaspect of the present invention, a terminal device that transmits asignal to a base station apparatus through uplink may include: atransmission unit that transmits to the base station apparatus a firstMAC control element which includes a first buffer size field indicatingan amount of first data available for transmission within a first bufferfor the uplink, and that transmits to the base station apparatus asecond MAC control element which includes a second buffer size fieldindicating an amount of second data available for transmission within asecond buffer for a first link that is used for communication betweenthe terminal device and a different terminal device, in which, in a casewhere a first parameter that is indicated with a higher layer is notconfigured, a value that is used in the first buffer size field may beconstituted in such a manner as to be indicated with a first table, inwhich, in the case where the first parameter is configured, the valuethat is used in the first buffer size field may be constituted in such amanner as to be indicated with a second table different from the firsttable, and in which a value that is used in the second buffer size fieldmay be constituted in such a manner as to be indicated at all times withthe first table.

(2) Furthermore, according to the aspect of the present invention, eachof the first table and the second table that are used in the terminaldevice may be constituted in such a manner as to indicate acorrespondence between a value of the buffer size and an index, and anindex in the second table may be constituted in such a manner as toindicate a value of an extended buffer size rather than a value of abuffer size to which an index in the first table corresponds.

(3) Furthermore, according to the aspect of the present invention, thefollowing table (1) may be constituted in such a manner as to be used asthe first table that is used in the terminal device, and the followingtable (2) may be constituted in such a manner as to be used as thesecond table.

TABLE 1 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 102 10 < BS <= 12 3 12 < BS <= 14 4 14 < BS <= 17 5 17 < BS <= 19 6 19 <BS <= 22 7 22 < BS <= 26 8 26 < BS <= 31 9 31 < BS <= 36 10 36 < BS <=42 11 42 < BS <= 49 12 49 < BS <= 57 13 57 < BS <= 67 14 67 < BS <= 7815 78 < BS <= 91 16  91 < BS <= 107 17 107 < BS <= 125 18 125 < BS <=146 19 146 < BS <= 171 20 171 < BS <= 200 21 200 < BS <= 234 22 234 < BS<= 274 23 274 < BS <= 321 24 321 < BS <= 376 25 376 < BS <= 440 26 440 <BS <= 515 27 515 < BS <= 603 28 603 < BS <= 706 29 706 < BS <= 826 30826 < BS <= 967 31  967 < BS <= 1132 32 1132 < BS <= 1326 33 1326 < BS<= 1552 34 1552 < BS <= 1817 35 1817 < BS <= 2127 36 2127 < BS <= 249037 2490 < BS <= 2915 38 2915 < BS <= 3413 39 3413 < BS <= 3995 40 3995 <BS <= 4677 41 4677 < BS <= 5476 42 5476 < BS <= 6411 43 6411 < BS <=7505 44 7505 < BS <= 8787 45  8787 < BS <= 10287 46 10287 < BS <= 1204347 12043 < BS <= 14099 48 14099 < BS <= 16507 49 16507 < BS <= 19325 5019325 < BS <= 22624 51 22624 < BS <= 26487 52 26487 < BS <= 31009 5331009 < BS <= 36304 54 36304 < BS <= 42502 55 42502 < BS <= 49759 5649759 < BS <= 58255 57 58255 < BS <= 68201 58 68201 < BS <= 79846 5979846 < BS <= 93479 60  93479 < BS <= 109439 61 109439 < BS <= 128125 62128125 < BS <= 150000 63 BS > 150000

TABLE 2 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 102 10 < BS <= 13 3 13 < BS <= 16 4 16 < BS <= 19 5 19 < BS <= 23 6 23 <BS <= 29 7 29 < BS <= 35 8 35 < BS <= 43 9 43 < BS <= 53 10 53 < BS <=65 11 65 < BS <= 80 12 80 < BS <= 98 13  98 < BS <= 120 14 120 < BS <=147 15 147 < BS <= 181 16 181 < BS <= 223 17 223 < BS <= 274 18 274 < BS<= 337 19 337 < BS <= 414 20 414 < BS <= 509 21 509 < BS <= 625 22 625 <BS <= 769 23 769 < BS <= 945 24  945 < BS <= 1162 25 1162 < BS <= 142926 1429 < BS <= 1757 27 1757 < BS <= 2161 28 2161 < BS <= 2657 29 2657 <BS <= 3267 30 3267 < BS <= 4017 31 4017 < BS <= 4940 32 4940 < BS <=6074 33 6074 < BS <= 7469 34 7469 < BS <= 9185 35  9185 < BS <= 11294 3611294 < BS <= 13888 37 13888 < BS <= 17077 38 17077 < BS <= 20999 3920999 < BS <= 25822 40 25822 < BS <= 31752 41 31752 < BS <= 39045 4239045 < BS <= 48012 43 48012 < BS <= 59039 44 59039 < BS <= 72598 4572598 < BS <= 89272 46  89272 < BS <= 109774 47 109774 < BS <= 134986 48134986 < BS <= 165989 49 165989 < BS <= 204111 50 204111 < BS <= 25099051 250990 < BS <= 308634 52 308634 < BS <= 379519 53 379519 < BS <=466683 54 466683 < BS <= 573866 55 573866 < BS <= 705666 56 705666 < BS<= 867737 57  867737 < BS <= 1067031 58 1067031 < BS <= 1312097 591312097 < BS <= 1613447 60 1613447 < BS <= 1984009 61 1984009 < BS <=2439678 62 2439678 < BS <= 3000000 63 BS > 3000000

(4) Furthermore, according to another aspect of the present invention, aterminal device that transmits a signal to a base station apparatusthrough uplink may include: a transmission unit that transmits to thebase station apparatus a first MAC control element which includes afirst buffer size field indicating an amount of first data available fortransmission within a first buffer for the uplink, and that transmits tothe base station apparatus a second MAC control element which includes asecond buffer size field indicating an amount of second data availablefor transmission within a second buffer for a first link that is usedfor communication between the terminal device and a different terminaldevice, in which, in a case where a first parameter that is indicatedwith a higher layer is not configured, a correspondence between a valuethat is used in the first buffer size field and the amount of the firstdata available for transmission within the first buffer may beconstituted in such a manner as to be indicated by a firstcorrespondence that is given with a first table, in which, in the casewhere the first parameter is configured, the correspondence between thevalue that is used in the first buffer size field and the amount of thefirst data available for transmission within the first buffer may beconstituted in such a manner to be indicated by a second correspondencethat is given with a second table different from the first table, and inwhich a correspondence between a value that is used in the second buffersize field and an amount of second data available for transmissionwithin the second buffer may be constituted in such a manner as to beindicated by the first correspondence.

(5) Furthermore, according to still another aspect of the presentinvention, an integrated circuit that is built into a terminal devicewhich transmits a signal to a base station apparatus through uplink maycause the terminal device to perform a sequence of functions thatincludes: a function of transmitting to the base station apparatus afirst MAC control element which includes a first buffer size fieldindicating an amount of first data available for transmission within afirst buffer for the uplink, and of transmitting to the base stationapparatus a second MAC control element which includes a second buffersize field indicating an amount of second data available fortransmission within a second buffer for a first link that is used forcommunication between the terminal device and a different terminaldevice, in which, in a case where a first parameter that is indicatedwith a higher layer is not configured, a value that is used in the firstbuffer size field may constituted in such a manner as to be indicatedwith a first table, in which, in the case where the first parameter isconfigured, the value that is used in the first buffer size field may beconstituted in such a manner as to be indicated with a second tabledifferent from the first table, and in which a value that is used in thesecond buffer size field may be constituted in such a manner as to beindicated at all times with the first table.

(6) Furthermore, in the integrated circuit according to the aspect ofthe present invention, each of the first table and the second table thatare used in the terminal device may be constituted in such a manner asto indicate a correspondence between a value of the buffer size and anindex, and an index in the second table may be constituted in such amanner as to indicate a value of an extended buffer size rather than avalue of a buffer size to which an index in the first table corresponds.

(7) Furthermore, in the integrated circuit according to the aspect ofthe present invention, the following table (3) is used as the firsttable that is used in the terminal device, and the following table (4)is used as the second table.

TABLE 3 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 102 10 < BS <= 12 3 12 < BS <= 14 4 14 < BS <= 17 5 17 < BS <= 19 6 19 <BS <= 22 7 22 < BS <= 26 8 26 < BS <= 31 9 31 < BS <= 36 10 36 < BS <=42 11 42 < BS <= 49 12 49 < BS <= 57 13 57 < BS <= 67 14 67 < BS <= 7815 78 < BS <= 91 16  91 < BS <= 107 17 107 < BS <= 125 18 125 < BS <=146 19 146 < BS <= 171 20 171 < BS <= 200 21 200 < BS <= 234 22 234 < BS<= 274 23 274 < BS <= 321 24 321 < BS <= 376 25 376 < BS <= 440 26 440 <BS <= 515 27 515 < BS <= 603 28 603 < BS <= 706 29 706 < BS <= 826 30826 < BS <= 967 31  967 < BS <= 1132 32 1132 < BS <= 1326 33 1326 < BS<= 1552 34 1552 < BS <= 1817 35 1817 < BS <= 2127 36 2127 < BS <= 249037 2490 < BS <= 2915 38 2915 < BS <= 3413 39 3413 < BS <= 3995 40 3995 <BS <= 4677 41 4677 < BS <= 5476 42 5476 < BS <= 6411 43 6411 < BS <=7505 44 7505 < BS <= 8787 45  8787 < BS <= 10287 46 10287 < BS <= 1204347 12043 < BS <= 14099 48 14099 < BS <= 16507 49 16507 < BS <= 19325 5019325 < BS <= 22624 51 22624 < BS <= 26487 52 26487 < BS <= 31009 5331009 < BS <= 36304 54 36304 < BS <= 42502 55 42502 < BS <= 49759 5649759 < BS <= 58255 57 58255 < BS <= 68201 58 68201 < BS <= 79846 5979846 < BS <= 93479 60  93479 < BS <= 109439 61 109439 < BS <= 128125 62128125 < BS <= 150000 63 BS > 150000

TABLE 4 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 102 10 < BS <= 13 3 13 < BS <= 16 4 16 < BS <= 19 5 19 < BS <= 23 6 23 <BS <= 29 7 29 < BS <= 35 8 35 < BS <= 43 9 43 < BS <= 53 10 53 < BS <=65 11 65 < BS <= 80 12 80 < BS <= 98 13  98 < BS <= 120 14 120 < BS <=147 15 147 < BS <= 181 16 181 < BS <= 223 17 223 < BS <= 274 18 274 < BS<= 337 19 337 < BS <= 414 20 414 < BS <= 509 21 509 < BS <= 625 22 625 <BS <= 769 23 769 < BS <= 945 24  945 < BS <= 1162 25 1162 < BS <= 142926 1429 < BS <= 1757 27 1757 < BS <= 2161 28 2161 < BS <= 2657 29 2657 <BS <= 3267 30 3267 < BS <= 4017 31 4017 < BS <= 4940 32 4940 < BS <=6074 33 6074 < BS <= 7469 34 7469 < BS <= 9185 35  9185 < BS <= 11294 3611294 < BS <= 13888 37 13888 < BS <= 17077 38 17077 < BS <= 20999 3920999 < BS <= 25822 40 25822 < BS <= 31752 41 31752 < BS <= 39045 4239045 < BS <= 48012 43 48012 < BS <= 59039 44 59039 < BS <= 72598 4572598 < BS <= 89272 46  89272 < BS <= 109774 47 109774 < BS <= 134986 48134986 < BS <= 165989 49 165989 < BS <= 204111 50 204111 < BS <= 25099051 250990 < BS <= 308634 52 308634 < BS <= 379519 53 379519 < BS <=466683 54 466683 < BS <= 573866 55 573866 < BS <= 705666 56 705666 < BS<= 867737 57  867737 < BS <= 1067031 58 1067031 < BS <= 1312097 591312097 < BS <= 1613447 60 1613447 < BS <= 1984009 61 1984009 < BS <=2439678 62 2439678 < BS <= 3000000 63 BS > 3000000

(8) Furthermore, according to still another aspect of the presentinvention, an integrated circuit that is built into a terminal devicethat transmits a signal to a base station apparatus through uplink maycause the terminal device to perform a sequence of functions thatincludes: a function of transmitting to the base station apparatus afirst MAC control element which includes a first buffer size fieldindicating an amount of first data available for transmission within afirst buffer for the uplink, and of transmitting to the base stationapparatus a second MAC control element which includes a second buffersize field indicating an amount of second data available fortransmission within a second buffer for a first link that is used forcommunication between the terminal device and a different terminaldevice, in which, in a case where a first parameter that is indicatedwith a higher layer is not configured, a correspondence between a valuethat is used in the first buffer size field and the amount of the firstdata available for transmission within the first buffer may beconstituted in such a manner as to be indicated by a firstcorrespondence that is given with a first table, in which, in the casewhere the first parameter is configured, the correspondence between thevalue that is used in the first buffer size field and the amount of thefirst data available for transmission within the first buffer may beconstituted in such a manner as to be indicated by a secondcorrespondence that is given with a second table different from thefirst table, and in which a correspondence between a value that is usedin the second buffer size field and an amount of second data availablefor transmission within the second buffer may be constituted in such amanner as to be indicated by the first correspondence.

(9) Furthermore, according to still another aspect of the presentinvention, a wireless communication method that is used in a terminaldevice that transmits a signal to a base station apparatus throughuplink may include: transmitting to the base station apparatus a firstMAC control element which includes a first buffer size field indicatingan amount of first data available for transmission within a first bufferfor the uplink, and transmitting to the base station apparatus a secondMAC control element which includes a second buffer size field indicatingan amount of second data available for transmission within a secondbuffer for a first link that is used for communication between theterminal device and a different terminal device, in which, in a casewhere a first parameter that is indicated with a higher layer is notconfigured, a value that is used in the first buffer size field may beconstituted in such a manner as to be indicated with a first table, inwhich, in the case where the first parameter is configured, the valuethat is used in the first buffer size field may be constituted in such amanner as to be indicated with a second table different from the firsttable, and in which a value that is used in the second buffer size fieldmay be constituted in such a manner as to be indicated at all times withthe first table.

(10) Furthermore, in the wireless communication method according to theaspect of the present invention, each of the first table and the secondtable that are used in the terminal device may be constituted in such amanner as to indicate a correspondence between a value of the buffersize and an index, and an index in the second table may be constitutedin such a manner as to indicate a value of an extended buffer sizerather than a value of a buffer size to which an index in the firsttable corresponds.

(11) Furthermore, in the wireless communication method according to theaspect of the present invention, the following table (5) may beconstituted in such a manner as to be used as the first table that isused in the terminal device, and the following table (6) may beconstituted in such a manner as to be used as the second table.

TABLE 5 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 102 10 < BS <= 12 3 12 < BS <= 14 4 14 < BS <= 17 5 17 < BS <= 19 6 19 <BS <= 22 7 22 < BS <= 26 8 26 < BS <= 31 9 31 < BS <= 36 10 36 < BS <=42 11 42 < BS <= 49 12 49 < BS <= 57 13 57 < BS <= 67 14 67 < BS <= 7815 78 < BS <= 91 16  91 < BS <= 107 17 107 < BS <= 125 18 125 < BS <=146 19 146 < BS <= 171 20 171 < BS <= 200 21 200 < BS <= 234 22 234 < BS<= 274 23 274 < BS <= 321 24 321 < BS <= 376 25 376 < BS <= 440 26 440 <BS <= 515 27 515 < BS <= 603 28 603 < BS <= 706 29 706 < BS <= 826 30826 < BS <= 967 31  967 < BS <= 1132 32 1132 < BS <= 1326 33 1326 < BS<= 1552 34 1552 < BS <= 1817 35 1817 < BS <= 2127 36 2127 < BS <= 249037 2490 < BS <= 2915 38 2915 < BS <= 3413 39 3413 < BS <= 3995 40 3995 <BS <= 4677 41 4677 < BS <= 5476 42 5476 < BS <= 6411 43 6411 < BS <=7505 44 7505 < BS <= 8787 45  8787 < BS <= 10287 46 10287 < BS <= 1204347 12043 < BS <= 14099 48 14099 < BS <= 16507 49 16507 < BS <= 19325 5019325 < BS <= 22624 51 22624 < BS <= 26487 52 26487 < BS <= 31009 5331009 < BS <= 36304 54 36304 < BS <= 42502 55 42502 < BS <= 49759 5649759 < BS <= 58255 57 58255 < BS <= 68201 58 68201 < BS <= 79846 5979846 < BS <= 93479 60  93479 < BS <= 109439 61 109439 < BS <= 128125 62128125 < BS <= 150000 63 BS > 150000

TABLE 6 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 102 10 < BS <= 13 3 13 < BS <= 16 4 16 < BS <= 19 5 19 < BS <= 23 6 23 <BS <= 29 7 29 < BS <= 35 8 35 < BS <= 43 9 43 < BS <= 53 10 53 < BS <=65 11 65 < BS <= 80 12 80 < BS <= 98 13  98 < BS <= 120 14 120 < BS <=147 15 147 < BS <= 181 16 181 < BS <= 223 17 223 < BS <= 274 18 274 < BS<= 337 19 337 < BS <= 414 20 414 < BS <= 509 21 509 < BS <= 625 22 625 <BS <= 769 23 769 < BS <= 945 24  945 < BS <= 1162 25 1162 < BS <= 142926 1429 < BS <= 1757 27 1757 < BS <= 2161 28 2161 < BS <= 2657 29 2657 <BS <= 3267 30 3267 < BS <= 4017 31 4017 < BS <= 4940 32 4940 < BS <=6074 33 6074 < BS <= 7469 34 7469 < BS <= 9185 35  9185 < BS <= 11294 3611294 < BS <= 13888 37 13888 < BS <= 17077 38 17077 < BS <= 20999 3920999 < BS <= 25822 40 25822 < BS <= 31752 41 31752 < BS <= 39045 4239045 < BS <= 48012 43 48012 < BS <= 59039 44 59039 < BS <= 72598 4572598 < BS <= 89272 46  89272 < BS <= 109774 47 109774 < BS <= 134986 48134986 < BS <= 165989 49 165989 < BS <= 204111 50 204111 < BS <= 25099051 250990 < BS <= 308634 52 308634 < BS <= 379519 53 379519 < BS <=466683 54 466683 < BS <= 573866 55 573866 < BS <= 705666 56 705666 < BS<= 867737 57  867737 < BS <= 1067031 58 1067031 < BS <= 1312097 591312097 < BS <= 1613447 60 1613447 < BS <= 1984009 61 1984009 < BS <=2439678 62 2439678 < BS <= 3000000 63 BS > 3000000

(12) Furthermore, according to still another aspect of the presentinvention, a wireless communication method that is used in a terminaldevice which transmits a signal to a base station apparatus throughuplink may include: transmitting to the base station apparatus a firstMAC control element which includes a first buffer size field indicatingan amount of first data available for transmission within a first bufferfor the uplink, and transmitting to the base station apparatus a secondMAC control element which includes a second buffer size field indicatingan amount of second data available for transmission within a secondbuffer for a first link that is used for communication between theterminal device and a different terminal device, in which, in a casewhere a first parameter that is indicated with a higher layer is notconfigured, a correspondence between a value that is used in the firstbuffer size field and the amount of the first data available fortransmission within the first buffer may be constituted in such a manneras to be indicated by a first correspondence that is given with a firsttable, in which, in the case where the first parameter is configured,the correspondence between the value that is used in the first buffersize field and the amount of the first data available for transmissionwithin the first buffer may be constituted in such a manner as to beindicated by a second correspondence that is given with a second tabledifferent from the first table, and in which a correspondence between avalue that is used in the second buffer size field and an amount ofsecond data available for transmission within the second buffer may beconstituted in such a manner as to be indicated by the firstcorrespondence.

Effects of the Invention

According to the invention, processing associated with a Buffer StatusReport (BSR) or a Scheduling Request (SR) can be efficiently performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual diagram of a wireless communication systemaccording to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a schematic constitution of a radioframe according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating a constitution of a slot according tothe embodiment of the present invention.

FIG. 4 is a diagram illustrating one example of a constitution of an MACPDU according to the embodiment of the present invention.

FIG. 5 is a diagram illustrating one example of a constitution of aC-RNTI MAC CE according to the embodiment of the present invention.

FIG. 6 is a diagram illustrating one example of a constitution of a PHMAC CE according to the embodiment of the present invention.

FIG. 7 is a diagram illustrating one example of a constitution of a BSRMAC CE that uses a Short BSR according to the embodiment of the presentinvention.

FIG. 8 is a diagram illustrating one example of a constitution of a BSRMAC CE that uses a long BSR according to the embodiment of the presentinvention.

FIG. 9 is a diagram illustrating one example of a buffer size referencethat is indicated by a 6-bit buffer size field according to theembodiment of the present invention.

FIG. 10 is a diagram illustrating one example of an extended buffer sizereference that is indicated by a 6-bit buffer size field according tothe embodiment of the present invention.

FIG. 11 is a diagram illustrating one example of a constitution of a D2DBSR MAC CE that uses a second Short BSR according to the embodiment ofthe present invention.

FIG. 12 is a diagram illustrating one example of the constitution of theD2D BSR MAC CE that uses a third Short BSR according to the embodimentof the present invention.

FIG. 13 is a diagram illustrating one example of the constitution of theD2D BSR MAC CE that uses a middle BSR according to the embodiment of thepresent invention.

FIG. 14 is a diagram illustrating one example of a buffer size referencethat is indicated by an 8-bit buffer size field according to theembodiment of the present invention.

FIG. 15 is a diagram illustrating one example of a buffer size referencethat is indicated by a 4-bit buffer size field according to theembodiment of the present invention.

FIG. 16 is a diagram illustrating one example of a logical channel IDfor a UL-SCH according to the embodiment of the present invention.

FIG. 17 is a diagram illustrating another example of the logical channelID for the UL-SCH according to the embodiment of the present invention.

FIG. 18 is a schematic block diagram illustrating a constitution of abase station apparatus 3 according to the embodiment of the presentinvention.

FIG. 19 is a schematic block diagram illustrating a constitution of aterminal device 1 according to the embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below.

According to the present embodiment, one or multiple cells areconfigured for a terminal device. A technology in which the terminaldevice performs communication through multiple cells is referred to ascell aggregation or carrier aggregation. The present invention may beapplied to each of the multiple cells that are configured for theterminal device. Furthermore, the present invention may be applied tosome of the multiple cells that are configured. A cell that isconfigured for the terminal device is also referred to as a servingcell.

Multiple serving cells that are configured include one primary cell, orone or multiple secondary cells. The primary cell is a serving cell inwhich an initial connection establishment procedure is executed, aserving cell in which a connection re-establishment procedure isstarted, or a cell that is indicated as a primary cell during a handoverprocedure. At a point in time at which a Radio Resource Control (RRC)connection is established, or later, the secondary cell may beconfigured.

In the case of the cell aggregation, a Time Division Duplex (TDD) schemeor a Frequency Division Duplex (FDD) scheme may be applied to allmultiple cells. Furthermore, a cell to which the TDD scheme is appliedand a cell to which the FDD scheme is applied may be aggregated.

FIG. 1 is a conceptual diagram of a wireless communication systemaccording to the present embodiment. In FIG. 1, the wirelesscommunication system includes terminal devices 1A to 1C, a repeater 2,and a base station apparatus 3. The terminal devices 1A to 1C arereferred to as a terminal device 1. The repeater 2 has a function ofamplifying a signal that is received from the terminal device 1 and oftransmitting the amplified signal. A serving cell 4 indicates an areathat is covered by the base station apparatus 3 (LTE).

An uplink 5 is a link from the terminal device 1 to the base stationapparatus 3. Moreover, in the uplink 5, a signal may be transmitteddirectly from the terminal device 1 to the base station apparatus 3without involving the repeater. A downlink 7 is a link from the basestation apparatus 3 to the terminal device 1. Furthermore, the uplink 5and the downlink 7 are also referred to as a cellular link or a cellularcommunication path. Furthermore, communication between the terminaldevice 1 and the base station apparatus 3 is also referred to ascellular communication.

A D2D link 9 is a link between the terminal devices 1. Moreover, the D2Dlink 9 is also referred to as a D2D communication path, a ProSe link, ora ProSe communication path. D2D discovery and D2D communication areperformed over the D2D link 9. The D2D discovery is a process/procedurethat specifies that the terminal device 1 is in proximity to a differentterminal device 1 using EUTRA. The D2D communication is communicationbetween two terminal devices 1 that are in proximity to each other usingan EUTRAN communication path that is established between the twoterminal devices 1. For example, the communication path may beestablished directly between the terminal devices 1.

Moreover, the D2D link 9 may include a ProSe-assisted Wireless LocalArea Network (WLAN) direct channel. For example, two terminal devices 1that are in proximity to each other may be discovered based on the D2Ddiscovery, EUTRAN may provide configuration information on a WLAN to thetwo terminal devices 1, and based on the configuration information onthe WLAN, the two terminal devices 1 may establish the ProSe-assistedWLAN direct communication path. For example, the two terminal devices 1that are in proximity to each other may be discovered based on the D2Ddiscovery that uses EUTRAN, and the EUTRAN communication path or theProSe-assisted Wireless Local Area Network (WLAN) direct communicationpath may be established between the two terminal devices 1 that arediscovered.

Radio resource allocation methods in a case where, in this manner, theUE performs D2D communication using the D2D link 9 include two modes,that is, mode 1 and mode 2. Mode 1 is a mode in which the base stationapparatus 3 schedules a resource that is used for the terminal device 1to transmit a data signal or a control signal over the D2D link 9.However, the base station apparatus 3 may a relay station. The mode 2 isa mode in which the terminal device 1 itself selects the resource thatis used for the terminal device 1 to transmit the data signal or thecontrol signal over the D2D link 9, from a pool of available radioresources, and uses the selected resource. For the mode 2, the pool ofavailable radio resources may be in advance determined, may be notifiedby the base station apparatus 3, and may be configured by a higherlayer.

A physical channel and a physical signal according to the presentembodiment are described.

The downlink physical channel and the downlink physical signal arecollectively referred to as a downlink signal. An uplink physicalchannel and an uplink physical signal are collectively referred to as anuplink signal. The physical channel is used for transmitting informationthat is output from the higher layer. The physical signal is not usedfor transmitting the information that is output from the higher layer,but is used by a physical layer.

In FIG. 1, the following uplink physical channels are used for uplinkwireless communication.

-   -   Physical Uplink Control Channel (PUCCH)    -   Physical Uplink Shared Channel (PUSCH)    -   Physical Random Access Channel (PRACH)

The PUCCH is a physical channel that is used for transmitting UplinkControl Information (UCI). Pieces of Uplink Control Information includeChannel State Information (CSI) for downlink, a Scheduling Request (SR)indicating a request for a PUSCH resource, and an acknowledgement(ACK)/negative-acknowledgement (NACK) of downlink data (a Transportblock or a Downlink-Shared Channel (DL-SCH)). The ACK/NACK is alsoreferred to as a HARQ-ACK or HARQ feedback.

The PUSCH is a physical channel that is used for transmitting uplinkdata (Uplink-Shared Channel (UL-SCH)) and/or the HARQ-ACK and/or theChannel State Information.

The PRACH is a physical channel that is used for transmitting a randomaccess preamble. The PRACH is used for the initial connectionestablishment procedure, the handover procedure, and the connectionre-establishment procedure.

In FIG. 1, the following uplink physical signals are used for the uplinkwireless communication.

-   -   Uplink Reference Signal (UL RS)

According to the present embodiment, the following two types of UplinkReference Signals are used.

-   -   Demodulation Reference Signal (DMRS)    -   Sounding Reference Signal (SRS)

The DMRS is associated with transmission of the PUSCH or the PUCCH. TheDMRS is time-multiplexed along with the PUSCH or the PUCCH. The basestation apparatus 3 uses the DMRS in order to perform channelreconfiguration of the PUSCH or the PUCCH. Transmission of both of thePUSCH and the DMRS is referred to simply as transmission of the PUSCH.Transmission of both of the PUCCH and the DMRS is referred to simply astransmission of the PUCCH. The SRS is not associated with thetransmission of the PUSCH or the PUCCH. The base station apparatus 3uses the SRS in order to measure an uplink channel state.

In FIG. 1, the following downlink physical channels are used fordownlink wireless communication.

-   -   Physical Broadcast Channel (PBCH)    -   Physical Control Format Indicator Channel (PCFICH)    -   Physical Hybrid automatic repeat request Indicator Channel        (PHICH)    -   Physical Downlink Control Channel (PDCCH)    -   Enhanced Physical Downlink Control Channel (EPDCCH)    -   Physical Downlink Shared Channel (PDSCH)    -   Physical Multicast Channel (PMCH)

The PBCH is used for broadcasting a Master Information Block (MIB)(Broadcast Channel (BCH)) that is used in a shared manner in theterminal device 1. For example, the MIB includes information indicatingan SFN. The system frame number (SFN) is a radio frame number. The MIBis system information.

The PCFICH is used for transmitting information that indicates a region(an OFDM symbol) which is used for transmission of the PDCCH.

The PHICH is used for transmitting an HARQ indicator (the HARQ feedback)indicating an ACKnowledgement (ACK) of or a Negative ACKnowledgement(NACK) of the uplink data (Uplink Shared Channel (UL-SCH)) that isreceived by the base station apparatus 3.

The PDCCH and the EPDCCH are used for transmitting Downlink ControlInformation (DCI). The downlink control information is also referred toas a DCI format. The Downlink Control Information includes a downlinkgrant and an uplink grant. The downlink grant is also referred to asdownlink assignment or downlink allocation.

The uplink grant is used for scheduling of a single PUSCH within asingle cell. The uplink grant is used for the scheduling of a singlePUSCH within a certain subframe. The downlink grant is used forscheduling of a single PDSCH within a single cell. The downlink grant isused for scheduling of the PDSCH within a subframe that is the same asthe subframe in which the downlink grant is transmitted.

A Cyclic Redundancy Check (CRC) parity bit is attached to the DCIformat. The CRC parity bit is scrambled with a Cell-Radio NetworkTemporary Identifier (C-RNTI). The C-RNTI is an identifier foridentifying the terminal device 1 within a cell. The C-RNTI is used forcontrolling a resource of the PDSCH or a resource for the PUSCH within asingle subframe.

The PDSCH is used for transmitting the downlink data (Downlink SharedChannel (DL-SCH)).

The PMCH is used for transmitting multicast data (Multicast Channel(MCH)).

In FIG. 1, the following downlink physical signals are used for thedownlink wireless communication.

-   -   Synchronization Signal (SS)    -   Downlink Reference Signal (DL RS)

The synchronization signal is used in order for the terminal device 1 tobe synchronized to a frequency domain and a time domain for thedownlink. In the FDD scheme, the synchronization signal is mapped tosubframes 0 and 5 within the radio frame.

The Downlink Reference Signal is used in order for the terminal device 1to perform the channel reconfiguration of the downlink physical channel.The Downlink Reference Signal is used in order for the terminal device 1to calculate the Channel State Information for the downlink. TheDownlink Reference Signal is used in order for the terminal device 1 tomeasure a geographical location of the terminal device 1 itself.

In FIG. 1, the following D2D physical channels are used for wirelesscommunication over the D2D link 9 between the terminal devices 1.

-   -   Physical D2D Control Channel (PD2DCCH)    -   Physical D2D Data Channel (PD2DDCH)

The PD2DCCH is a physical channel that is used for transmitting D2D linkcontrol information. The D2D link control information includesinformation indispensable for the terminal device 1 that receives a D2Dsignal to perform decoding. For example, pieces of information may beincluded such as an identifier of the terminal device 1 that receivesD2D transmission data, a Modulation and Coding Scheme (MCS) that is usedfor the D2D transmission data, and a resource arrangement.

The PD2DDCH is a physical channel that is used for transmitting the D2Dtransmission data. However, a name of the above-mentioned D2D physicalchannel is one example, and other names thereof may be used.Furthermore, for the wireless communication over the D2D link 9 betweenthe terminal devices 1, the Downlink Physical Channel or the UplinkPhysical Channel may be used. The signal (the physical channel and thephysical signal) that is transmitted and received over the D2D link 9are also referred to as a signal that is used for the D2D, a signal forthe D2D, or a D2D signal.

A logical channel will be described below. The logical channels definetypes of data transmission sizes that are transmitted and received witha Medium Access Control (MAC) layer. The logical channels include thefollowing channels.

-   -   Broadcast Control Channel (BCCH)    -   Paging Control Channel (PCCH)    -   Common Control Channel (CCCH)    -   Dedicated Control Channel (DCCH)    -   Dedicated Traffic Channel (DTCH)

The BCCH is a downlink channel that is used for broadcasting systeminformation.

The PCCH is a downlink channel that is used for transmitting paginginformation, and is used when a network does not know a cell position ofthe terminal device.

The CCCH is a channel that is used for transmitting control informationbetween the terminal device and the network, and is used by the terminaldevice that does not have a Radio Resource Control (RRC) connection tothe network.

The DCCH is a point-to-point bidirectional channel, and is a channelthat is used for transmitting individual control information between theterminal device and the network.

The DCCH is used by the terminal device that has the RRC connection.

The DTCH is a point-to-point bidirectional channel, is a channeldedicated for one terminal device, and is used for transfer of userinformation (unicast data).

The BCH, the MCH, the UL-SCH, and the DL-SCH are transport channels. Achannel that is used in the Medium Access Control (MAC) layer isreferred to as a transport channel. A unit of data for the transportchannel that is used in the MAC layer is also referred to as a transportblock (TB) or a MAC Protocol Data Unit (PDU). Control of a HybridAutomatic Repeat Request (HARQ) is performed for every transport blockin the MAC layer. The transport block is a unit of data that the MAClayer delivers to the physical layer. In the physical layer, thetransport block is mapped to a codeword, and coding processing isperformed on every codeword.

A structure of the radio frame according to the present embodiment isdescribed.

In LTE, two structures of the radio frame are supported. The twostructures of the radio frame are frame structure type 1 and framestructure type 2. Frame structure type 1 is applicable to FDD. Framestructure type 2 is applicable to TDD.

FIG. 2 is a diagram illustrating a schematic constitution of the radioframe according to the present embodiment. In FIG. 2, the horizontalaxis is a time axis.

Furthermore, each of a type 1 radio frame and a type 2 radio frame is 10ms long, and is defined by 10 subframes. Each of the subframes is 1 mslong, and is defined by two consecutive slots. Slots are each 0.5 mslong. An i-th subframe within the radio frame is constituted from a(2×i)-th slot and a (2×i+1)-th slot.

The following three types of subframes are defined for frame structuretype 2.

-   -   downlink subframe    -   uplink subframe    -   special subframe

The downlink subframe is a subframe that is reserved for downlinktransmission. The uplink subframe is a subframe that is reserved foruplink transmission. The special subframe is configured from threefields. The three fields are a Downlink Pilot Time Slot (DwPTS), a GuardPeriod (GP), and an Uplink Pilot Time Slot (UpPTS). A sum of lengths ofthe DwPTS, the GP, and the UpPTS is 1 ms long. The DwPTS is a field thatis reserved for the downlink transmission. The UpPTS is a field that isreserved for the uplink transmission. The GP is a field, the downlinktransmission and the uplink transmission on which are not performed.Moreover, the special subframe may be constituted only from the DwPTSand the GP, and may be constituted only from the GP and the UpPTS.

A radio frame of frame structure type 2 is constituted at least from thedownlink subframe, the uplink subframe, and the special subframe.

A constitution of the slot according to the present embodiment isdescribed.

FIG. 3 is a diagram illustrating the constitution of the slot accordingto the present embodiment. In FIG. 3, a normal Cyclic Prefix (CP) isapplied to the OFDM symbol or an SC-FDMA symbol. The physical signal orthe physical channel that is transmitted on each of the slots isexpressed by a resource grid. In FIG. 3, the horizontal axis is a timeaxis and the vertical axis is a frequency axis. In the downlink, theresource grid is defined by multiple subcarriers and multiple OFDMsymbols. In uplink, the resource grid is defined by multiple subcarriersand multiple SC-FDMA symbols. For example, in a D2D link, the resourcegrid may be defined by multiple subcarriers and multiple SC-FDMAsymbols. The number of subcarriers that constitute one slot depends on acell bandwidth. The number of OFDM symbols or SC-FDMA symbols thatconstitute one slot is 7. Each of the elements within the resource gridis referred to as a resource element. The resource element is identifiedusing a subcarrier number, and an OFDM symbol or SC-FDMA symbol number.

A resource block is used for expressing mapping of a certain physicalchannel (the PDSCH, the PUSCH, or the like) to resource elements. Theresource block is defined by a virtual resource block and a physicalresource block. A certain physical channel is first mapped to thevirtual resource block. Thereafter, the virtual resource block is mappedto the physical resource block. One physical resource block is definedby 7 consecutive OFDM symbols or SC-FDMA symbols in the time domain andby 12 consecutive subcarriers in the frequency domain. Therefore, onephysical resource block is constituted from (7×12) resource elements.Furthermore, one physical resource block corresponds to one slot in thetime domain, and corresponds to 180 kHz in the frequency domain. Thephysical resource blocks are numbered from 0 in the frequency domain.

Moreover, an extended CP may be applied to the OFDM symbol or theSC-FDMA symbol. In the case of the extended CP, the number of OFDMsymbols or SC-FDMA symbols that constitute one slot is 7.

FIG. 4 illustrates one example of the MAC PDU according to the presentembodiment. One MAC PDU is constituted from one MAC header, 0 or moreMAC Service Data Units (MAC SDUs), 0 or more MAC Control Element (MACCE), and padding.

The MAC header is constituted from multiple subheaders, and eachsubheader corresponds to the MAC SDU, the MAC CE, and the padding withinthe same MAC PDU. Included in the subheader is information, such as asize of the corresponding MAC SDU or MAC CE, or a padding bit, if needarises, in addition to the corresponding MAC SDU or MAC CE, or what isindicated by a logical channel ID of padding. One example of a logicalchannel ID within the subheader will be described below.

The MAC CEs that are applicable in the MAC PDU which is mapped to theUL-SCH include BSR MAC CE (which, in some cases, is referred to as anMAC BSR CE) for reporting a Buffer Status Report (BSR) for uplink, a D2DBSR MAC CE for reporting the BSR in the D2D link, a C-RNTI MAC CE fornotifying the Cell-Radio Network Temporary Identifier (C-RNTI), and a PHMAC CE for reporting a Power Headroom (PH) (capacity available fortransmit power).

The BSR MAC CE is used for providing information relating to an amountof data available for transmission, which is included in an uplinkbuffer or a D2D buffer in the terminal device 1, to the base stationapparatus 3. The D2D BSR MAC CE is used for providing informationrelating to the amount of data available for transmission, which isincluded in the D2D buffer in the terminal device 1, to the base stationapparatus 3. The BSR will be described below.

The C-RNTI MAC CE includes a C-RNTI for identifying by which terminaldevice within a cell a signal is transmitted. FIG. 5 is one exampleillustrating a constitution of the C-RNTI MAC CE. The C-RNTI MAC CE isconstituted from a C-RNTI field that includes a C-RNTI of the terminaldevice. The C-RNTI field is 16 bits (2 octets) long. The C-RNTI MAC CEis identified by the corresponding MAC PDU subheader.

The PH MAC CE is used for the PH that provides the base stationapparatus 3 with information relating to a difference between nominal UEmaximum transmit power of the terminal device 1 for every serving cellwhich is activated and power that is obtained for transmission of theUL-SCH, and information relating to a difference between the nominal UEmaximum transmit power of the terminal device 1 in the primary cell andpower that is obtained for transmission of the UL-SCH and the PUCCH.FIG. 6 is one example illustrating a constitution of the PH MAC CE. ThePH MAC CE is constituted from 8 bits (one octet), which are a sum ofreserved two bits that are set to 0 and 6 bits for a PH field indicatingthe PH. The PH MAC CE is identified by the corresponding MAC PDUsubheader. However, in a case where transmission is performed usingmultiple serving cells, an extended PH MAC CE for notifying the PH forevery serving cell may be used.

The BSR and the Scheduling Request (SR) according to the presentembodiment will be described below.

In a case where the uplink data or D2D data available for transmissionin the terminal device 1 occurs and where a UL-SCH resource is notallocated, the SR is transmitted to the base station apparatus 3 usingthe PUCCH that is allocated from the base station apparatus 3. Forexample, the uplink data is data on the logical channel in the uplink.For example, the D2D data is data on the logical channel in the D2Dlink.

Moreover, in a case where the D2D data available for transmission in theterminal device 1 occurs and where the UL-SCH resource is not allocated,the terminal device 1 for which mode 2 is configured may not transmitthe SR to the base station apparatus 3 using the PUCCH that is allocatedfrom the base station apparatus 3.

That is, in a case where the D2D data available for transmission in theterminal device 1 for which mode 1 is configured occurs, and where theUL-SCH resource is not allocated, the SR is triggered. Furthermore, in acase where the D2D data available for transmission in the terminaldevice 1 for which the mode 2 is configured occurs, and where the UL-SCHresource is not allocated, the SR is not triggered. The terminal device1 on which reconfiguration from mode 1 to mode 2 is performed may cancelthe SR that is triggered only for the reason that the D2D data availablefor transmission in the terminal device 1 occurs and that the UL-SCHresource is not allocated.

After the SR is transmitted, in a case where the UL-SCH is allocatedfrom the base station apparatus 3, the terminal device 1 transmits theBSR indicating buffer status information on the uplink data or the D2Ddata of the terminal device 1 to the base station apparatus 3 on theUL-SCH resource that is allocated. According to the present embodiment,the BSR for the uplink transmission data is referred to as an uplinkBSR, and the BSR for the D2D transmission data is referred to as a D2DBSR. In a case where the uplink BSR is received from the terminal device1, the base station apparatus 3 performs scheduling of the uplink datato the terminal device 1. In a case where the D2D BSR is received fromthe terminal device 1, the base station apparatus 3 performs schedulingof the D2D data to the terminal device 1.

After the SR is transmitted, in a case where the UL-SCH is not allocatedfrom the base station apparatus 3, the terminal device 1 transmits theSR again. Although retransmission of the SR is repeated a prescribednumber of times, in a case where the UL-SCH is not allocated from thebase station apparatus 3, the terminal device 1 releases the PUCCH andthe SRS that are allocated, and thus executes a random access procedure.

Next, the uplink BSR according to the present embodiment will bedescribed below.

In the uplink, logical channels are categorized into Logical ChannelGroups (LCGs). With the uplink BSR, an amount of transmission databuffer for the uplink data that corresponds to each LCG is notified, asa message of the MAC layer, to the base station apparatus.

According to a triggering condition, the uplink BSRs includes a regularBSR, a periodic BSR, and a padding BSR.

In a case where data on a logical channel that belongs to a certain LCGis available for transmission, and where the data has a higher prioritylevel than the logical channel that is already available fortransmission, which belongs to any one of the LCGs, or in a case wheredata available for transmission is not present on the logical channelthat belongs to any one of the LCGS, the regular BSR is triggered.Furthermore, in a case where a prescribed retransmission timerretxBSR-Timer expires, and where the UE has data available fortransmission on the logical channel that belongs to a certain LCG, theregular BSR is triggered.

In a case where a prescribed timer periodic BSR-Timer expires, theperiodic BSR is triggered.

In a case where the UL-SCH is allocated and where the number of paddingbits is equal to or greater than sizes of the BSR MAC CE and thesubheader thereof, the padding BSR is triggered.

Furthermore, a format for the MAC CE on which the uplink BSR istransmitted includes a Long BSR, a Short BSR, and a Truncated BSR.

FIG. 7 illustrates one example of a constitution of the Long BSR or theShort BSR in a case where the number of LCGs is 4. In FIG. 7, the ShortBSR or the Truncated BSR is constituted from 8 bits (one octet), whichare a sum of a 2-bit LCG ID field indicating for which LCG the BufferStatus Report is and a 6-bit buffer size field indicating a buffer sizeof the LCG, and it is possible that the Buffer Status Report for one LCGis transmitted.

The buffer size field indicates a total amount of available data that isdelivered to all logical channels in the logical channel group after allMAC PDUs are built at Transmission Time Interval (TTI).

FIG. 8 indicates one example of a constitution of the long BSR in a casewhere the number of LCGs is 4. In FIG. 8, the Long BSR is constitutedfrom 24 bits (3 octets), which are a sum of bits for four buffer sizefields that indicate buffer sizes of LCGs that have LCG IDs #0 to #3,respectively, and it is possible that the Buffer Status Reports for allfour LCGs are transmitted.

One example of a buffer size reference that is indicated by 6-bit buffersize fields for the Short BSR, the Truncated BSR, and the Long BSR isillustrated in FIGS. 9 and 10. In a case where a parameterextendedBSR-Sizes for the higher layer is not configured, the terminaldevice 1 uses the buffer size reference that is illustrated in FIG. 9.In a case where extendedBSR-Sizes is configured, the terminal device 1uses an extended buffer size reference that is illustrated in FIG. 10.

In a case where the regular BSR and the periodic BSR are performed, ifdata available for transmission on two or more LCGs is present at theTTI at which the BSR is transmitted, the terminal device 1 reports theLong BSR. If not, the terminal device 1 reports the Short BSR.

In a case where the padding BSR is performed, if, at the TTI at whichthe BSR is transmitted, the number of padding bits is equal to orgreater than sizes of a MAC CE on which the Long BSR is transmitted andof a subheader thereof, the terminal device 1 reports the Long BSR. In acase where the number of padding bits is less than the sizes of the MACCE on which the Long BSR is transmitted and of the subheader thereof,but is equal to or greater than sizes of a MAC CE on which the Short BSRis transmitted and of a subheader thereof, the terminal device 1performs a subsequent operation. In a case where data available fortransmission on two or more LCGs is present, the Truncated BSR for theLCG that has the highest priority level is reported. In the other cases,the Short BSR is reported.

The uplink BSRs that are all triggered are canceled in the followingcases.

(1) A case where the BSR is included in the MAC PDU

(2) A case where all pieces of uplink data within the buffer areavailable for transmission on the UL-SCH that is allocated by the uplinkgrant, but a resource is insufficient for sending added BSR MAC CE and asubheader thereof.

Next, the D2D BSR according to the present embodiment will be describedbelow.

With the D2D BSR, an amount of buffer for the D2D transmission data onthe logical channel that is usable for the D2D communication isnotified, as the message of the MAC layer, to the base stationapparatus. One aspect of the D2D BSR is that with the D2D BSR, an amountof buffer for the transmission data on the logical channel is notifiedwith the logical channel usable for the D2D communication as one type.However, in a case where there are two or more types of logical channelsthat are usable for the D2D communication, the amount of buffer for thetransmission data on each logical channel or the amount of buffer forthe transmission data on every LCG that is made up of two or more typesof logical channels may be notified as is the case with the uplink BSR.Furthermore, as is the case with the uplink BSR, the triggeringcondition for the D2D BSR may be that all of the regular BSR, theperiodic BSR, and the padding BSR are used, and only some of thetriggering conditions may be used.

Next, a format for the D2D BSR MAC CE is described.

For the D2D BSR MAC CE, the Short BSR or the Truncated BSR in FIG. 7 andthe Long BSR in FIG. 8, each of which is the same format as for theuplink BSR, may be used, and different formats may be used. For example,in a case where the number of LCGs that are used for the D2D is 1, asillustrated in FIG. 11, an LCG ID format may not be used and a secondShort BSR may be used. For example, in a case where the number of LCGsthat are used for the D2D is 2, as illustrated in FIG. 12, a third ShortBSR may be used that uses two 4-bit buffer size fields that have LCG IDs#0 and #1. Furthermore, for example, in a case where the number of LCGsthat are used for the D2D is 4, as illustrated in FIG. 13, a middle BSRmay be used that is constituted from two octets that are used for four4-bit buffer size fields.

In a case where the same format as for the uplink BSR is used, for a6-bit buffer size field, the same buffer size reference and extendedbuffer size reference as for the uplink BSR can be used as illustratedin FIGS. 9 and 10. However, in a case where the buffer size referencethat is used for the uplink BSR is replaced with extendedBSR-Sizes, thebuffer size reference in FIG. 9 may be applied at all times for the D2DBSR. That is, in a case where extendedBSR-Sizes is set, the extendedbuffer reference may not be used for the D2D BSR.

Furthermore, for the D2D BSR, a parameter for the higher layer withwhich the buffer size reference is replaced may be used independently ofthe uplink. In this case, in a case where distribution of buffer sizesfor the uplink BSR and distribution of buffer sizes for the D2D BSR aredifferent from each other, different buffer size references can beconfigured.

However, for the D2D BSR, a buffer size reference that is different fromthat for the uplink BSR may be used. For example, an 8-bit buffer sizereference that is illustrated in FIG. 14 may be used, and a 4-bit buffersize reference that is illustrated in FIG. 15 may be used. Accordingly,it is possible that the second Short BSR or the third Short BSR isapplied.

FIG. 16 illustrates one example of the logical channel ID for the UL-SCHaccording to the present embodiment. With a 5-bit logical channel IDthat is shown for every MAC PDU subheader in the MAC PDU header, thebase station apparatus can identify the corresponding MAC CE, MAC SDU,and padding.

However, in FIG. 16, this is effectively possible in a case where onlyone type of D2D BSR format (for example, the Short BSR) is used.However, a logical channel ID in FIG. 17 may be applied in a case wherethe Short BSR, the Truncated BSR, and the Long BSR are used for the D2DBSR.

In addition, a logical channel ID that is an arbitrary number may beapplied to the D2D BSR.

An operation that is performed by the terminal device according to thepresent invention in a case where multiple logical channels are includedin the uplink data that has to be transmitted will be described below.

The MAC layer has a function of mapping each logical channel to the MACPDU, and in a case where new transfer is performed, uses a LogicalChannel Prioritization (LCP) procedure. In a basic LCP procedure, atransmission priority level of the transmission data is determinedconsidering a priority level of each logical channel and a transmissionbit rate (Prioritized Bit Rate (PBR)) that has to be transmitted withina fixed period, which corresponds to Quality of Service (QoS) of a radiobearer, and mapping to the MAC PDU is performed starting from data withthe highest priority level at the point in time when the uplink grant isreceived.

The RRC layer controls the scheduling of the uplink data by signaling aparameter priority indicating that the greater a value is, the lower apriority is, a parameter prioritizedBitRate indicating a Prioritized BitRate (PBR), and a parameter bucketSizeDuration indicating a bucket sizeduration (BSD).

The terminal device 1 retains a variable Bj for each logical channel j.Bj is initialized to zero in a case where an associated logical channelis established, and a value (PBR×TTI duration) that is obtained bymultiplying the PBR or a TTI duration is added in the logical channel jat every TTI. However, in a case where a value of Bj does not exceed apacket size and the value of Bj is greater than a packet size of thelogical channel j, the value of Bj is set to the packet size. The packetsize in a certain logical channel is equal to PBR×BSD.

The terminal device 1 allocates a resource to the logical channelaccording to the following procedure.

Step 1: All logical channel satisfying Bj>0 are allocated in order oflowering priority level. In a case where a PBR of a certain radio beareris set to infinity, the terminal device 1 allocates a resource to dataavailable for transmission on all radio bearers before determining a PBRof another radio bearer that has a low priority level.

Step 2: The terminal device 1 subtracts from Bj a sum of sizes of theMAC SDUs that are allocated to the logical channel j in Step 1. However,Bj can take a negative value.

Step 3: In a case where there are unoccupied resources, all logicalchannels are allocated in order of lowering priority level regardless ofthe value of Bj until data on the logical channel or the uplink grant isnot present. Allocation is equally performed on the logical channelsthat have equal priority levels.

The priority levels in the LCP procedure according to the presentembodiment are arranged in order of lowering priority level as follows.

-   -   C-RNTI MAC CE or data from UL-CCCH    -   BSR MAC CE that excludes the padding BSR    -   D2D BSR MAC CE that excludes the padding BSR    -   PHR MAC CE or Extended PHR MAC CE    -   Data from the logical channels from which the UL-CCCH is        excluded    -   BSR MAC CE using the padding BSR    -   D2D BSR MAC CE using the padding BSR

In this manner, a higher priority level for the MAC CE for the uplinkBSR is configured than for the MAC CE for the D2D BSR, and thus in acase where the uplink BSR and the D2D BSR are triggered at the sametime, resources for allocating the BSR MAC CE can be precluded frombeing insufficient due to the allocation of the D2D BSR MAC CE.Notification of the uplink BSR is indispensable for the terminal device1 to allocate the uplink resource from the base station apparatus 3. Ina case where, for this reason, the D2D BSR MAC CE is allocated, and thusthe uplink BSR is not notified to the base station apparatus 3, it isconsidered that SR processing is sought for the uplink BSR, that a delayoccurs in allocation for uplink communication, and that communicationefficiency decreases.

However, a priority level of the D2D BSR MAC CE may differ from theperspective that the MAC CE relating to the uplink takes precedence overthe MAC CE relating to the D2D. For example, the D2D BSR MAC CE may havea lower priority level than the PHR MAC CE or the Extended PHR MAC CE,and may have a lower priority level than data from the logical channelsfrom which the UL-CCCH is excluded.

However, an arbitrary priority level may be configured between the BSRMAC CE using the padding BSR and the D2D BSR MAC CE using the paddingBSR.

For example, in a case where the Short BSR, the Truncated BSR, and theLong BSR are usable with the BSR MAC CE and where only the Short BSR isusable with the D2D BSR MAC CE, the terminal device 1 may perform thefollowing operation according to the number of padding bits.

In a case where the number of padding bits is equal to or greater thansizes of one Short BSR and a subheader thereof and is smaller than sizesof two Short BSRs and subheaders thereof, the terminal device 1 performsthe following operation.

-   -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on the uplink is not present and data        available for transmission with the D2D is present, the D2D BSR        that uses the Short BSR is transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on two or more LCGs in the uplink is        present, the uplink BSR that uses the Truncated BSR for the LCG        that has the highest priority level is transmitted.    -   In the other cases, the uplink BSR that uses the Short BSR is        transmitted.

In a case where the number of padding bits is equal to or greater thansizes of two Short BSRs and subheaders thereof and is smaller than sizesof one Long BSR and a subheader thereof, the terminal device 1 performsthe following operation.

-   -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission with the D2D is present, the D2D BSR        that uses the Short BSR is transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on two or more LCGs in the uplink is        present, the uplink BSR that uses the Truncated BSR for the LCG        that has the highest priority level is transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on one LCG in the uplink is present,        or in a case where data available for transmission on the uplink        is not present, the uplink BSR that uses the Short BSR is        transmitted.

In a case where the number of padding bits is equal to or greater thansizes of one Long BSR and a subheader thereof and is smaller than sizesof one Long BSR, one Short BSR, and subheaders of these, the terminaldevice 1 performs the following operation.

-   -   In the case where at the TTI at which the BSR is transmitted,        the data available for transmission on two or more LCGs in the        uplink is present, the uplink BSR that uses the Long BSR is        transmitted.    -   In the case where at the TTI at which the BSR is transmitted,        the data available for transmission on one LCG in the uplink is        present, or in the case where the data available for        transmission on the uplink is not present, the uplink BSR that        uses the Short BSR and the D2D BSR that uses the Short BSR are        transmitted.

In a case where the number of padding bits is equal to or greater thansizes of one Long BSR, one Short BSR, and subheaders of these, theterminal device 1 performs the following operation.

-   -   At the TTI at which the BSR is transmitted, the uplink BSR that        uses the Long BSR and the D2D BSR that uses the Short BSR are        transmitted.

Furthermore, in a case where each of the Short BSR, the Truncated BSR,and the Long BSR is usable with the BSR MAC CE and the D2D BSR MAC CE,the terminal device 1 may perform the following operation according tothe number of padding bits.

In the case where the number of padding bits is equal to or greater thansizes of one Short BSR and a subheader thereof and is smaller than sizesof two Short BSRs and subheaders thereof, the terminal device 1 performsthe following operation.

-   -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on the uplink is not present and data        available for transmission on two or more LCGs for the D2D is        present, the D2D BSR that uses the Truncated BSR for the LCG        that has the highest priority level is transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on the uplink is not present and data        available for transmission on one LCG for the D2D is present,        the D2D BSR that uses the Short BSR is transmitted.    -   In the case where at the TTI at which the BSR is transmitted,        the data available for transmission on two or more LCGs in the        uplink is present, the uplink BSR that uses the Truncated BSR        for the LCG that has the highest priority level is transmitted.    -   In the other cases, the uplink BSR that uses the Short BSR is        transmitted.

In the case where the number of padding bits is equal to or greater thansizes of two Short BSRs and subheaders thereof and is smaller than sizesof one Long BSR and a subheader thereof, the terminal device 1 performsthe following operation.

-   -   In a case where at the TTI at which the BSR is transmitted, the        data available for transmission on two or more LCGs for the D2D        is present, the D2D BSR that uses the Truncated BSR for the LCG        that has the highest priority level is transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on one LCG for the D2D is present, or        in a case where data available for transmission with the D2D is        not present, the D2D BSR that uses the Short BSR is transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on two or more LCGs in the uplink is        present, the uplink BSR that uses the Truncated BSR for the LCG        that has the highest priority level is transmitted.    -   In the case where at the TTI at which the BSR is transmitted,        the data available for transmission on one LCG in the uplink is        present, or in the case where the data available for        transmission on the uplink is not present, the uplink BSR that        uses the Short BSR is transmitted.

In the case where the number of padding bits is equal to or greater thansizes of one Long BSR and a subheader thereof and is smaller than sizesof one Long BSR, one Short BSR, and subheaders of these, the terminaldevice 1 performs the following operation.

-   -   In the case where at the TTI at which the BSR is transmitted,        the data available for transmission on two or more LCGs in the        uplink is present, the uplink BSR that uses the Long BSR is        transmitted.    -   In a case where at the TTI at which the BSR is transmitted, the        data available for transmission on the uplink is not present and        data available for transmission on two or more LCGs in the D2D        link is present, the D2D BSR that uses the Long BSR is        transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on one LCG in the uplink is present        and data available for transmission on two or more LCGs in the        D2D link is present, the uplink BSR that uses the Short BSR and        the D2D BSR that uses the Truncated BSR for the LCG that has the        highest priority level in the D2D link are transmitted.    -   In the other cases, the uplink BSR that uses the Short BSR and        the D2D BSR that uses the Short BSR are transmitted.

In a case where the number of padding bits is equal to or greater thansizes of one Long BSR, one Short BSR, and subheaders of these and issmaller than sizes of two Long BSRs, and subheaders of these, theterminal device 1 performs the following operation.

-   -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on two or more LCGs with the D2D is        not present, the uplink BSR that uses the Long BSR and the D2D        BSR that uses the Short BSR are transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on two LCGs in the uplink is not        present and data available for transmission on two or more LCGs        for the D2D is present, the uplink BSR that uses the Short BSR        and the D2D BSR that uses the Long BSR are transmitted.    -   In a case where at the TTI at which the BSR is transmitted, data        available for transmission on two or more LCGs in the uplink is        present and data available for transmission on two or more LCGs        for the D2D is present, the uplink BSR that uses the Long BSR        and the D2D BSR that uses the Truncated BSR for the LCG that has        the highest priority level in the D2D link are transmitted.

In a case where the number of padding bits is equal to or greater thansizes of two or more Long BSRs and subheaders of these, the uplink BSRthat uses the Long BSR and the D2D BSR that uses the Long BSR aretransmitted.

With this operation, the uplink BSR and the D2D BSR can be efficientlytransmitted using the padding bit.

However, the uplink BSR is described above as taking precedence over theD2D BSR in a case where the padding BSR is transmitted, but it iseffectively possible that the D2D BSR also takes precedence in thetransmission. In this case, for the regular BSR or the periodic BSR, theuplink BSR takes precedence over the D2D BSR, and thus the D2D BSR thatuses the padding BSR can compensate for the missing of opportunity forthe transmission of the D2D BSR.

However, in a case where the padding BSR is transmitted, an arbitraryBSR that is selected by the terminal device 1 from the uplink BSR andthe D2D BSR may be transmitted.

However, in the case where the padding BSR is transmitted, the uplinkBSR and the D2D BSR may be alternately transmitted. That is, of theuplink BSR and the D2D BSR, the BSR that is not transmitted with thelast padding BSR may be transmitted.

Furthermore, in a case where at one TTI, the terminal device 1 isrequested to transmit multiple MAC PDUs, the terminal device 1 mayperform some or all of the following operations.

-   -   The uplink BSR and the D2D BSR are included in the same MAC PDU,        or in different MAC PDUs.    -   The padding BSR for the uplink is included in the MAC PDU that        does not include the regular BSR for the uplink or the periodic        BSR for the uplink.    -   The padding BSR for the D2D link is included in the MAC PDU that        does not include the regular BSR for the D2D link and the        periodic BSR for the D2D link.

For example, in a case where at one TTI, the terminal device 1 isrequested to transmit multiple MAC PDUs and the regular BSR, theperiodic BSR, or the padding BSR for the uplink are included in a firstMAC PDU, the regular BSR, the periodic BSR, or the padding BSR for theD2D link may be included in a second MAC PDU.

For example, in a case where at one TTI, the terminal device 1 isrequested to transmit multiple MAC PDUs, and the regular/periodic BSRfor the uplink, and the padding BSR for the D2D link are included in thefirst MAC PDU, the regular/periodic BSR for the D2D link and the paddingBSR for the uplink may be included in the second MAC PDU, and thepadding BSR for the uplink and the padding BSR for the D2D link may beincluded in the third MAC PDU.

However, it is desirable that only at most one BSR MAC CE and one D2DBSR MAC CE are included in one MAC PDU. In a case where, in thiscondition, at a timing at which it is possible that the BSR istransmitted, multiple events trigger the uplink BSR, the regular BSR andthe periodic BSR take precedence over the padding BSR. In the casewhere, in this condition, at the time at which it is possible that theBSR is transmitted, multiple events trigger the D2D BSR, the regular BSRand the periodic BSR take precedence over the padding BSR.

Furthermore, only at most one BSR MAC CE or one D2D BSR MAC CE may beincluded in the MAC PDU. In a case where, in this condition, at thetiming at which it is possible that the BSR is transmitted, multipleevents trigger the uplink BSR and the D2D BSR, it is desirable that theD2D BSR using the padding BSR takes precedence over the uplink BSR usingthe regular BSR and the periodic BSR.

As described above, with the uplink BSR and the D2D BSR, different MACCEs (the BSR MAC CE and the D2D BSR MAC CE) are defined. However,according to another aspect of the present invention, it is effectivelypossible that the D2D BSR is allocated to one LCG that is notified bythe uplink BSR. For example, in a case where four LCGs are used for theBSR MAC CE, one LCG may be allocated to the D2D BSR. Which LCG isallocated to the D2D BSR, for example, may be determined as is the casewith LCG ID #4, and may be configured by higher layer signaling.

A constitution of the device according to the present embodiment will bedescribed below.

FIG. 18 is a schematic block diagram illustrating a constitution of thebase station apparatus 3 according to the present embodiment. Asillustrated, the base station apparatus 3 is constituted to include alogical channel allocation unit 301, a transmission unit 302, areception unit 303, a MAC information detection unit 304, a resourceallocation unit 305, and a transmit and receive antenna unit 306. Thelogical channel allocation unit 301 allocates an identificationinformation on the logical information to the terminal device 1. Forexample, in addition to an identifier of each logical channel, thepriority level of each logical channel, the PBR, the BSD, and the like,which are described above, are included in the identificationinformation of the logical channel.

The transmission unit 302 is constituted in such a manner as to transmita data signal or a control signal to the terminal device 1 through thetransmit and receive antenna unit 306. However, the transmission unit302 is constituted in such a manner as to transmit the identificationinformation on the logical channel that is allocated by the logicalchannel allocation unit 301. Furthermore, the transmission unit 302 isconstituted in such a manner as to transmit each of the allocationinformation on the uplink resource and the allocation information on aD2D resource to the terminal device 1 at a prescribed timing. The uplinkresource and the D2D resource are allocated by the resource allocationunit 305 to the terminal device 1.

The reception unit 303 is constituted in such a manner as to receivethrough the transmit and receive antenna unit 306 the data signal or thecontrol signal that is transmitted from the terminal device 1.

The MAC information detection unit 304 detects the MAC PDU from thesignal that is received in the reception unit 303, and, with a MACsubheader that is included in the MAC PDU, detects each MAC CE thatincludes information, such as the C-RNTI, the BSR, or the PH, from theMAC PDU.

The resource allocation unit 305 allocates the uplink resource to eachterminal device 1, taking into consideration an amount of uplink bufferdata for every terminal device 1 that is indicated by the BSR MAC CEwhich is detected in the MAC information detection unit 304. Theresource allocation unit 305 allocates the D2D resource to each terminaldevice 1, taking into consideration an amount of D2D buffer data forevery terminal device 1 that is indicated by the D2D BSR MAC CE. Piecesof information on the uplink resource and the D2D resource, which areallocated, are output to the transmission unit 302.

FIG. 19 is a schematic block diagram illustrating a constitution of theterminal device 1 according to the present embodiment. As illustrated,the terminal device 1 is constituted to include a reception unit 101, anuplink buffer 102, a D2D buffer 103, a BSR generation unit 104, a MACinformation generation unit 105, a transmission unit 106, and a transmitand receive antenna unit 107.

The reception unit 101 is constituted in such a manner as to receivethrough the transmit and receive antenna unit 107 the data signal or thecontrol signal that is transmitted from the base station apparatus 3 ora different terminal device 1. Furthermore, the reception unit 101receives the identification information on the logical channel and theallocation information on the uplink resource or the D2D resource, whichare transmitted from the base station apparatus 3.

The uplink buffer 102 is constituted in such a manner as to temporarilyretain uplink data until transmission of the uplink data to the basestation apparatus 3 is completed in a case where the uplink data that isto be transmitted to the base station apparatus 3 occurs. The D2D buffer103 is constituted in such a manner as to temporarily retain the D2Dtransmission data until the transmission of the D2D transmission data tothe different terminal device 1 is completed in a case where the D2Dtransmission data that is to be transmitted to the different terminaldevice 1 occurs. However, the same storage region may be used in ashared manner in the uplink buffer 102 and the D2D buffer 103.

At a prescribed timing, the BSR generation unit 104 generates the uplinkBSR for notifying an amount of uplink data for every LCG that isretained within the uplink buffer 102. At a prescribed timing, the BSRgeneration unit 104 generates the D2D BSR for notifying an amount of D2Dtransmission data for every LCG (or every logical channel) that isretained within the D2D buffer 103. The uplink BSR and the D2D BSR,which are generated, are output, as BSR information, to the MACinformation generation unit 105.

The MAC information generation unit 105 is constituted in such a manneras to generate the MAC CE from information relating to the C-RNTI, orthe BSR, or the PH and to generate the MAC PDU for notifying the basestation apparatus 3 of the generated MAC CE with the transmission dataincluded. At this point, the MAC information generation unit 105generates the MAC PDU based on the LCP procedure described above based.Specifically, in a case where all of the MAC CEs and all pieces oftransmission data are difficult to allocate for a size of the MAC PDUbased on the allocated uplink resource, some of the MAC CEs and thepieces of transmission data are dropped based on the priority level ofeach of the MAC CEs and the pieces of transmission data.

The transmission unit 106 is constituted in such a manner as to transmituplink data signal or control signal to the base station apparatus 3through the transmit and receive antenna unit 107. The transmission unit106 is constituted in such a manner as to transmit the D2D signal to thedifferent terminal device 1 through the transmit and receive antennaunit 107.

It is apparent from above that the terminal device 1 according to thepresent embodiment may have various features as follows.

A terminal device 1 according to the present embodiment, which is aterminal device 1 that performs cellular communication (which is herereferred to as first communication) with a base station apparatus 3(which is here referred to as an E-UTRAN) and D2D communication (whichis here referred to as second communication) between terminal devices 1,includes a transmission unit 106 that reports an uplink BSR (which ishere referred to as a first Buffer Status Report) for the firstcommunication and a D2D BSR (which is here referred to as a secondBuffer Status Report) for the second communication, in uplink for thefirst communication, in which, in a logical channel prioritizationprocedure, a priority level of the first Buffer Status Report is higherthan a priority level of the second Buffer Status Report.

Furthermore, according to the present embodiment, the transmission unit106 of the terminal device 1 reports a power headroom report for thefirst communication in the uplink for the first communication, in which,in the logical channel prioritization procedure, the priority level ofthe second Buffer Status Report is higher than the priority level of thepower headroom report.

Furthermore, according to the present embodiment, the logical channelprioritization procedure in the terminal device 1 is applied in a casewhere initial transmission is performed.

Furthermore, according to the present embodiment, the terminal device 1allocates an uplink resource in order of lowering the priority level inthe logical channel prioritization procedure.

Furthermore, according to the present embodiment, the first BufferStatus Report by the terminal device 1 is a regular Buffer Status Report(regular BSR) for the first communication or a periodic Buffer StatusReport (periodic BSR) for the first communication, and the second BufferStatus Report is a regular Buffer Status Report for the secondcommunication or a periodic Buffer Status Report for the secondcommunication.

Furthermore, according to the present embodiment, the transmission unit106 of the terminal device 1 reports a third Buffer Status Report (forexample, which is the uplink BSR that uses a padding BSR) for the firstcommunication and a fourth Buffer Status Report (for example, which isthe D2D BSR that uses the padding BSR) for the second communication inthe uplink for the first communication, in which, in the logical channelprioritization procedure, the priority level of the second Buffer StatusReport is higher than priority levels of the third Buffer Status Reportand the fourth Buffer Status Report.

Furthermore, according to the present embodiment, in the terminal device1, in a case where the first Buffer Status Report and the third BufferStatus Report are triggered, at most one Buffer Status Report of thefirst Buffer Status Report and the third Buffer Status Report isincluded in one MAC PDU, and the first Buffer Status Report takesprecedence over the third Buffer Status Report.

Furthermore, according to the present embodiment, in the terminal device1, in a case where the second Buffer Status Report and the fourth BufferStatus Report are triggered, at most one Buffer Status Report of thesecond Buffer Status Report and the fourth Buffer Status Report isincluded in one MAC PDU, and the second Buffer Status Report takesprecedence over the fourth Buffer Status Report.

Furthermore, according to the present embodiment, in a case where thefirst Buffer Status Report, the second Buffer Status Report, the thirdBuffer Status Report, and the fourth Buffer Status Report are triggeredand where the terminal device 1 is requested to transmit multiple MACPDUs at a certain TTI, the terminal device 1 includes the third BufferStatus Report in any MAC PDU that does not include the first BufferStatus Report, and includes the fourth Buffer Status Report in any MACPDU that does not include the second Buffer Status Report.

Furthermore, a terminal device 1 according to the present embodiment,which is a terminal device 1 that performs first communication with anE-UTRAN and second communication between terminal devices 1, includes atransmission unit 106 that transmits one or multiple MAC PDUs whichincludes a first Buffer Status Report MAC CE (for example, a BSR MAC CE)for the first communication and a second Buffer Status Report MAC CE(for example, a D2D BSR MAC CE) for the second communication, in uplinkfor the first communication, in which the first Buffer Status Report MACCE and the second Buffer Status Report MAC CE include a buffer sizefield that corresponds to a logical channel group, the buffer size fieldindicates a total amount of available data over all logical channels inthe corresponding logical channel group (LCG) after all MAC PDUsincluding the one or multiple MAC PDUs are built, a value of a bufferstatus field that is included in the first Buffer Status Report MAC CEis selected based on a buffer size reference (which is here referred toas a first table) associated with a value of a buffer size in a casewhere a first parameter (for example, extendedBSR-Sizes) is notconfigured, the value of the buffer status field that is included in thefirst Buffer Status Report MAC CE is selected based on an extendedbuffer size reference (which is here referred to as a second table) thatis different from the first table associated with the value of thebuffer size in a case where the first parameter is configured, and athird table that is used in a case where the value of the buffer statusfield that is included in the second Buffer Status Report MAC CE isselected does not depend on the first parameter.

Furthermore, according to the present embodiment, the third table thatis used in the case where the value of the buffer status field that isincluded in the second Buffer Status Report MAC CE by the terminaldevice 1 is the same table as the first table.

Furthermore, according to the present embodiment, each of the firsttable and the second table that are used in the terminal device 1indicates a correspondence between the value of the buffer size and anindex, and an index in the second table indicates a value of an extendedbuffer size rather than a value of a buffer size to which an index inthe first table corresponds.

Furthermore, according to the present embodiment, the number of bits ofthe buffer size field that is included in the second Buffer StatusReport which is used in the terminal device 1 is smaller than the numberof bits of the buffer size field that is included in the first BufferStatus Report.

Furthermore, a terminal device 1 according to the present embodiment,which is a terminal device 1 that performs first communication with anE-UTRAN and second communication between terminal devices 1, includes aconfiguration unit that configures a first mode (for example, mode 1) inwhich a resource for the second communication is controlled by theE-UTRAN, or a second mode (for example, mode 2) in which the resourcefor the second communication is selected by the terminal device 1 from apool of resources, and a transmission unit that reports a Buffer StatusReport for the second communication in uplink for the firstcommunication, in which, in a case where the second mode is configured,the Buffer Status Report for the second communication is not triggered.

Furthermore, in the terminal device 1 according to the presentembodiment, the Buffer Status Report for the second communication istriggered in a case where the first mode is configured.

Furthermore, in the terminal device 1 according to the presentembodiment, the triggered Buffer Status Report for the secondcommunication is cancelled in a case where the second mode is configuredor reconfigured.

Furthermore, according to the present embodiment, the Buffer StatusReport for the second communication by the terminal device 1 is aregular Buffer Status Report, and the regular Buffer Status Report forthe second communication is triggered based on an event, such as whenretxBSR-Timer expires and the terminal device 1 retains data availablefor transmission for the second communication.

Furthermore, in the terminal device 1 according to the presentembodiment, a scheduling request is triggered at least based on acondition that the Buffer Status Report for the second communication istriggered and is not cancelled, and the scheduling request is used forrequesting a UL-SCH resource for initial transmission in the uplink forthe first communication.

Furthermore, the terminal device 1 according to the present embodimentcancels the pending scheduling request that derives from the regularBuffer Status Report for the second communication that is based on theevent, in the case where the second mode is configured or reconfigured.

Furthermore, an integrated circuit according to the present embodiment,which is an integrated circuit that is built into a terminal device 1which performs first communication with an E-UTRAN and secondcommunication between terminal devices 1, causes the terminal device 1to perform a sequence of functions that includes a function of reportinga first Buffer Status Report for the first communication and a secondBuffer Status Report for the second communication, in uplink for thefirst communication, in which, in a logical channel prioritizationprocedure, a priority level of the first Buffer Status Report is higherthan a priority level of the second Buffer Status Report.

Furthermore, an integrated circuit according to the present embodiment,which is an integrated circuit that is built into a terminal device 1which performs first communication with an E-UTRAN and secondcommunication between terminal devices 1, causes the terminal device 1to perform a sequence of functions that includes a function oftransmitting one or multiple MAC PDUs which includes a first BufferStatus Report MAC CE for the first communication and a second BufferStatus Report MAC CE for the second communication, in uplink for thefirst communication, in which the first Buffer Status Report MAC CE andthe second Buffer Status Report MAC CE include a buffer size field thatcorresponds to a logical channel group, the buffer size field indicatesa total amount of available data over all logical channels in thecorresponding logical channel group after all MAC PDUs including the oneor multiple MAC PDUs are built, a value of a buffer status field that isincluded in the first Buffer Status Report MAC CE is selected based on afirst table associated with a value of a buffer size in a case where afirst parameter is not configured, the value of the buffer status fieldthat is included in the first Buffer Status Report MAC CE is selectedbased on a second table that is different from the first tableassociated with the value of the buffer size in a case where the firstparameter is configured, and a third table that is used in a case wherethe value of the buffer status field that is included in the secondBuffer Status Report MAC CE is selected does not depend on the firstparameter.

Furthermore, an integrated circuit according to the present invention,which is an integrated circuit that is built into a terminal device 1which performs first communication with an E-UTRAN and secondcommunication between terminal devices 1, causes the terminal device 1to perform a sequence of functions that includes a function ofconfiguring a first mode in which a resource for the secondcommunication is controlled by the E-UTRAN, or a second mode in whichthe resource for the second communication is selected by the terminaldevice 1 from the pool of resources, and a function of reporting aBuffer Status Report for the second communication in uplink for thefirst communication, in which, in a case where the second mode isconfigured, the Buffer Status Report for the second communication is nottriggered.

Furthermore, a wireless communication method according to the presentembodiment, which a wireless communication method that is used in aterminal device 1 which performs first communication with an E-UTRAN andsecond communication between terminal devices 1, includes reporting afirst Buffer Status Report for the first communication and a secondBuffer Status Report for the second communication, in uplink for thefirst communication, in which, in a logical channel prioritizationprocedure, a priority level of the first Buffer Status Report is higherthan a priority level of the second Buffer Status Report.

Furthermore, a wireless communication method according to the presentembodiment, which is a wireless communication method that is used in aterminal device 1 which performs first communication with an E-UTRAN andsecond communication between terminal devices 1, includes transmittingone or multiple MAC PDUs which includes a first Buffer Status Report MACCE for the first communication and a second Buffer Status Report MAC CEfor the second communication, in uplink for the first communication, inwhich the first Buffer Status Report MAC CE and the second Buffer StatusReport MAC CE include a buffer size field that corresponds to a logicalchannel group, the buffer size field indicates a total amount ofavailable data over all logical channels in the corresponding logicalchannel group after all MAC PDUs including the one or multiple MAC PDUsare built, a value of a buffer status field that is included in thefirst Buffer Status Report MAC CE is selected based on a first tableassociated with a value of a buffer size in a case where a firstparameter is not configured, the value of the buffer status field thatis included in the first Buffer Status Report MAC CE is selected basedon a second table that is different from the first table associated withthe value of the buffer size in a case where the first parameter isconfigured, and a third table that is used in a case where the value ofthe buffer status field that is included in the second Buffer StatusReport MAC CE is selected does not depend on the first parameter.

Furthermore, a wireless communication method according to the presentembodiment, which is a wireless communication method that is used in aterminal device 1 which performs first communication with an E-UTRAN andsecond communication between terminal devices 1, includes configuring afirst mode in which a resource for the second communication iscontrolled by the E-UTRAN, or a second mode in which the resource forthe second communication is selected by the terminal device 1 from thepool of resources, and reporting a Buffer Status Report for the secondcommunication in uplink for the first communication, in which, in a casewhere the second mode is configured, the Buffer Status Report for thesecond communication is not triggered.

A program running on the base station apparatus 3 and the terminaldevice 1 according to the present invention may be a program (a programfor causing a computer to operate) that controls a Central ProcessingUnit (CPU) and the like in such a manner as to realize the functionaccording to the embodiments of the present invention, which aredescribed above. Then, pieces of information that are handled in thedevice and the apparatus are temporarily stored in a Random AccessMemory (RAM) while being processed. Thereafter, the pieces ofinformation are stored in various types of ROMs such as a Flash ReadOnly Memory (ROM), or a Hard Disk Drive (HDD) and, if need arises, areread by the CPU to be modified or rewritten.

Moreover, one portion of each of the terminal device 1 and the basestation apparatus 3 according to the embodiments, which are describedabove, may be realized by the computer. In such a case, this one portionmay be realized by recording a program for realizing such a controlfunction on a computer-readable medium and causing a computer system toread the program stored on the recording medium for execution.

Moreover, the “computer system” here is defined as a computer systemthat is built into the terminal device 1 or the base station apparatus 3and as including an OS or hardware components such as a peripheraldevice. Furthermore, the “computer-readable recording medium” refers toa portable medium, such as a flexible disk, a magneto-optical disk, aROM, and a CD-ROM, and a storage device, such as a hard disk, that isbuilt into the computer system.

Moreover, the “computer-readable recording media” may include a mediumthat dynamically retains the program for a short period of time, such asa communication line that is available when transmitting the programover a network such as the Internet or over a communication network suchas a telephone network, and a medium that retains the program for afixed period of time, such as a volatile memory within the computersystem, which functions as a server or a client in a case where theprogram is retained dynamically for a short period of time. Furthermore,the program described above may be one for realizing some of thefunctions described above and additionally may be one that can realizethe functions described above in combination with a program that isalready recorded on the computer system.

Furthermore, the base station apparatus 3 according to the embodiment,which is described above, can be realized as an aggregation (anapparatus group) that is constituted from multiple apparatuses. Each ofthe apparatuses that constitute the apparatus group may be equipped withsome portions or all portions of each function of, or some portions orall portions of each functional block of the base station apparatus 3according to the embodiment, which is described. The apparatus groupitself may have each general function of or each general functionalblock of the base station apparatus 3. Furthermore, the terminal device1 according to the embodiment, which is described above, is also capableof communicating with the base station apparatus as an aggregation.

Furthermore, the base station apparatus 3 according to the embodiment,which is described above, may also be referred to as an EvolvedUniversal Terrestrial Radio Access Network (E UTRAN). Furthermore, thebase station apparatus 3 according to the embodiment, which is describedabove, may have some portions or all portions of a function of a nodethat is at a higher level than an eNodeB.

Furthermore, some portions or all portions of each of the terminaldevice 1 and the base station apparatus 3 according to the embodiment,which is described above, may be realized as an LSI that is a typicalintegrated circuit and may be realized as a chip set. Each functionalblock of the terminal device 1 and the base station apparatus 3 may beindividually realized into a chip, and some or all of the functionalblocks may be integrated into a chip. Furthermore, a circuit integrationtechnique is not limited to the LSI, and an integrated circuit for thefunctional block may be realized as a dedicated circuit or ageneral-purpose processor. Furthermore, if with advances insemiconductor technology, a circuit integration technology for a circuitwith which an LSI is replaced will appear, it is possible that anintegrated circuit to which such a technology is applied is also used.

Furthermore, according to the embodiments, which are described above,the terminal device is described as one example of a communicationdevice, but the present invention is not limited to this, and can alsobe applied to a terminal device or a communication apparatus, such as afixed-type electronic apparatus that is installed indoors or outdoors,or a stationary-type electronic apparatus, for example, an AV apparatus,a kitchen apparatus, a cleaning or washing machine, an air conditioner,office equipment, a vending machine, and other household apparatuses.

The embodiment of the invention is described in detail above referringto the drawings, but the specific configuration is not limited to theembodiment and also includes an amendment to a design and the like thatfall within the scope that does not depart from the gist of the presentinvention. Furthermore, various modifications are possible within thescope of the present invention defined by claims, and embodiments thatare implemented by suitably combining technical means that are disclosedaccording to different embodiments also falls within the technical scopeof the present invention. Furthermore, a configuration in which aconstituent element that achieves the same effect is substituted for theone that is described above according to each of the embodimentsdescribed above also falls within the technical scope of the presentinvention.

INDUSTRIAL APPLICABILITY

The present invention can be applied to a communication device, such asa portable telephone, a home electronic appliance, such as an AV system,and other electronic apparatus.

DESCRIPTION OF REFERENCE NUMERALS

-   -   1 (1A, 1B, 1C) TERMINAL DEVICE    -   2 REPEATER    -   3 BASE STATION APPARATUS    -   101 RECEPTION UNIT    -   102 UPLINK BUFFER    -   103 D2D BUFFER    -   104 BSR GENERATION UNIT    -   105 MAC INFORMATION GENERATION UNIT    -   106 TRANSMISSION UNIT    -   107 TRANSMIT AND RECEIVE ANTENNA    -   301 LOGICAL CHANNEL ALLOCATION UNIT    -   302 TRANSMISSION UNIT    -   303 RECEPTION UNIT    -   304 MAC INFORMATION DETECTION UNIT    -   305 RESOURCE ALLOCATION UNIT    -   306 TRANSMIT AND RECEIVE ANTENNA

1. A terminal device that transmits a signal to a base station apparatus through uplink, the terminal device comprising: a transmission unit that transmits to the base station apparatus a first MAC control element which includes a first buffer size field indicating an amount of first data available for transmission within a first buffer for the uplink, and that transmits to the base station apparatus a second MAC control element which includes a second buffer size field indicating an amount of second data available for transmission within a second buffer for a first link that is used for communication between the terminal device and a different terminal device, wherein, in a case where a first parameter that is indicated with a higher layer is not configured, a value that is used in the first buffer size field is indicated with a first table, wherein, in the case where the first parameter is configured, the value that is used in the first buffer size field is indicated with a second table different from the first table, and wherein a value that is used in the second buffer size field is indicated at all times with the first table.
 2. The terminal device according to claim 1, wherein each of the first table and the second table indicates a correspondence between a value of the buffer size and an index, and wherein an index in the second table indicates a value of an extended buffer size rather than a value of a buffer size to which an index in the first table corresponds.
 3. The terminal device according to claim 2, wherein the following table (7) is used as the first table, and the following table (8) is used as the second table. TABLE 7 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 10 2 10 < BS <= 12 3 12 < BS <= 14 4 14 < BS <= 17 5 17 < BS <= 19 6 19 < BS <= 22 7 22 < BS <= 26 8 26 < BS <= 31 9 31 < BS <= 36 10 36 < BS <= 42 11 42 < BS <= 49 12 49 < BS <= 57 13 57 < BS <= 67 14 67 < BS <= 78 15 78 < BS <= 91 16  91 < BS <= 107 17 107 < BS <= 125 18 125 < BS <= 146 19 146 < BS <= 171 20 171 < BS <= 200 21 200 < BS <= 234 22 234 < BS <= 274 23 274 < BS <= 321 24 321 < BS <= 376 25 376 < BS <= 440 26 440 < BS <= 515 27 515 < BS <= 603 28 603 < BS <= 706 29 706 < BS <= 826 30 826 < BS <= 967 31  967 < BS <= 1132 32 1132 < BS <= 1326 33 1326 < BS <= 1552 34 1552 < BS <= 1817 35 1817 < BS <= 2127 36 2127 < BS <= 2490 37 2490 < BS <= 2915 38 2915 < BS <= 3413 39 3413 < BS <= 3995 40 3995 < BS <= 4677 41 4677 < BS <= 5476 42 5476 < BS <= 6411 43 6411 < BS <= 7505 44 7505 < BS <= 8787 45  8787 < BS <= 10287 46 10287 < BS <= 12043 47 12043 < BS <= 14099 48 14099 < BS <= 16507 49 16507 < BS <= 19325 50 19325 < BS <= 22624 51 22624 < BS <= 26487 52 26487 < BS <= 31009 53 31009 < BS <= 36304 54 36304 < BS <= 42502 55 42502 < BS <= 49759 56 49759 < BS <= 58255 57 58255 < BS <= 68201 58 68201 < BS <= 79846 59 79846 < BS <= 93479 60  93479 < BS <= 109439 61 109439 < BS <= 128125 62 128125 < BS <= 150000 63 BS > 150000

TABLE 8 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 10 2 10 < BS <= 13 3 13 < BS <= 16 4 16 < BS <= 19 5 19 < BS <= 23 6 23 < BS <= 29 7 29 < BS <= 35 8 35 < BS <= 43 9 43 < BS <= 53 10 53 < BS <= 65 11 65 < BS <= 80 12 80 < BS <= 98 13  98 < BS <= 120 14 120 < BS <= 147 15 147 < BS <= 181 16 181 < BS <= 223 17 223 < BS <= 274 18 274 < BS <= 337 19 337 < BS <= 414 20 414 < BS <= 509 21 509 < BS <= 625 22 625 < BS <= 769 23 769 < BS <= 945 24  945 < BS <= 1162 25 1162 < BS <= 1429 26 1429 < BS <= 1757 27 1757 < BS <= 2161 28 2161 < BS <= 2657 29 2657 < BS <= 3267 30 3267 < BS <= 4017 31 4017 < BS <= 4940 32 4940 < BS <= 6074 33 6074 < BS <= 7469 34 7469 < BS <= 9185 35  9185 < BS <= 11294 36 11294 < BS <= 13888 37 13888 < BS <= 17077 38 17077 < BS <= 20999 39 20999 < BS <= 25822 40 25822 < BS <= 31752 41 31752 < BS <= 39045 42 39045 < BS <= 48012 43 48012 < BS <= 59039 44 59039 < BS <= 72598 45 72598 < BS <= 89272 46  89272 < BS <= 109774 47 109774 < BS <= 134986 48 134986 < BS <= 165989 49 165989 < BS <= 204111 50 204111 < BS <= 250990 51 250990 < BS <= 308634 52 308634 < BS <= 379519 53 379519 < BS <= 466683 54 466683 < BS <= 573866 55 573866 < BS <= 705666 56 705666 < BS <= 867737 57  867737 < BS <= 1067031 58 1067031 < BS <= 1312097 59 1312097 < BS <= 1613447 60 1613447 < BS <= 1984009 61 1984009 < BS <= 2439678 62 2439678 < BS <= 3000000 63 BS > 3000000


4. A terminal device that transmits a signal to a base station apparatus through uplink, the terminal device comprising: a transmission unit that transmits to the base station apparatus a first MAC control element which includes a first buffer size field indicating an amount of first data available for transmission within a first buffer for the uplink, and that transmits to the base station apparatus a second MAC control element which includes a second buffer size field indicating an amount of second data available for transmission within a second buffer for a first link that is used for communication between the terminal device and a different terminal device, wherein, in a case where a first parameter that is indicated with a higher layer is not configured, a correspondence between a value that is used in the first buffer size field and the amount of the first data available for transmission within the first buffer is indicated by a first correspondence that is given with a first table, wherein, in the case where the first parameter is configured, the correspondence between the value that is used in the first buffer size field and the amount of the first data available for transmission within the first buffer is indicated by a second correspondence that is given with a second table different from the first table, and wherein a correspondence between a value that is used in the second buffer size field and an amount of second data available for transmission within the second buffer is indicated by the first correspondence.
 5. An integrated circuit that is built into a terminal device which transmits a signal to a base station apparatus through uplink, the integrated circuit causing terminal device to perform a sequence of functions that comprises: a function of transmitting to the base station apparatus a first MAC control element which includes a first buffer size field indicating an amount of first data available for transmission within a first buffer for the uplink, and of transmitting to the base station apparatus a second MAC control element which includes a second buffer size field indicating an amount of second data available for transmission within a second buffer for a first link that is used for communication between the terminal device and a different terminal device, wherein, in a case where a first parameter that is indicated with a higher layer is not configured, a value that is used in the first buffer size field is indicated with a first table, wherein, in the case where the first parameter is configured, the value that is used in the first buffer size field is indicated with a second table different from the first table, and wherein a value that is used in the second buffer size field is indicated at all times with the first table.
 6. The integrated circuit according to claim 5, wherein each of the first table and the second table indicates a correspondence between a value of the buffer size and an index, and wherein an index in the second table indicates a value of an extended buffer size rather than a value of a buffer size to which an index in the first table corresponds.
 7. The terminal device according to claim 6, wherein the following table (9) is used as the first table, and the following table (10) is used as the second table. TABLE 9 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 10 2 10 < BS <= 12 3 12 < BS <= 14 4 14 < BS <= 17 5 17 < BS <= 19 6 19 < BS <= 22 7 22 < BS <= 26 8 26 < BS <= 31 9 31 < BS <= 36 10 36 < BS <= 42 11 42 < BS <= 49 12 49 < BS <= 57 13 57 < BS <= 67 14 67 < BS <= 78 15 78 < BS <= 91 16  91 < BS <= 107 17 107 < BS <= 125 18 125 < BS <= 146 19 146 < BS <= 171 20 171 < BS <= 200 21 200 < BS <= 234 22 234 < BS <= 274 23 274 < BS <= 321 24 321 < BS <= 376 25 376 < BS <= 440 26 440 < BS <= 515 27 515 < BS <= 603 28 603 < BS <= 706 29 706 < BS <= 826 30 826 < BS <= 967 31  967 < BS <= 1132 32 1132 < BS <= 1326 33 1326 < BS <= 1552 34 1552 < BS <= 1817 35 1817 < BS <= 2127 36 2127 < BS <= 2490 37 2490 < BS <= 2915 38 2915 < BS <= 3413 39 3413 < BS <= 3995 40 3995 < BS <= 4677 41 4677 < BS <= 5476 42 5476 < BS <= 6411 43 6411 < BS <= 7505 44 7505 < BS <= 8787 45  8787 < BS <= 10287 46 10287 < BS <= 12043 47 12043 < BS <= 14099 48 14099 < BS <= 16507 49 16507 < BS <= 19325 50 19325 < BS <= 22624 51 22624 < BS <= 26487 52 26487 < BS <= 31009 53 31009 < BS <= 36304 54 36304 < BS <= 42502 55 42502 < BS <= 49759 56 49759 < BS <= 58255 57 58255 < BS <= 68201 58 68201 < BS <= 79846 59 79846 < BS <= 93479 60  93479 < BS <= 109439 61 109439 < BS <= 128125 62 128125 < BS <= 150000 63 BS > 150000

TABLE 10 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 10 2 10 < BS <= 13 3 13 < BS <= 16 4 16 < BS <= 19 5 19 < BS <= 23 6 23 < BS <= 29 7 29 < BS <= 35 8 35 < BS <= 43 9 43 < BS <= 53 10 53 < BS <= 65 11 65 < BS <= 80 12 80 < BS <= 98 13  98 < BS <= 120 14 120 < BS <= 147 15 147 < BS <= 181 16 181 < BS <= 223 17 223 < BS <= 274 18 274 < BS <= 337 19 337 < BS <= 414 20 414 < BS <= 509 21 509 < BS <= 625 22 625 < BS <= 769 23 769 < BS <= 945 24  945 < BS <= 1162 25 1162 < BS <= 1429 26 1429 < BS <= 1757 27 1757 < BS <= 2161 28 2161 < BS <= 2657 29 2657 < BS <= 3267 30 3267 < BS <= 4017 31 4017 < BS <= 4940 32 4940 < BS <= 6074 33 6074 < BS <= 7469 34 7469 < BS <= 9185 35  9185 < BS <= 11294 36 11294 < BS <= 13888 37 13888 < BS <= 17077 38 17077 < BS <= 20999 39 20999 < BS <= 25822 40 25822 < BS <= 31752 41 31752 < BS <= 39045 42 39045 < BS <= 48012 43 48012 < BS <= 59039 44 59039 < BS <= 72598 45 72598 < BS <= 89272 46  89272 < BS <= 109774 47 109774 < BS <= 134986 48 134986 < BS <= 165989 49 165989 < BS <= 204111 50 204111 < BS <= 250990 51 250990 < BS <= 308634 52 308634 < BS <= 379519 53 379519 < BS <= 466683 54 466683 < BS <= 573866 55 573866 < BS <= 705666 56 705666 < BS <= 867737 57  867737 < BS <= 1067031 58 1067031 < BS <= 1312097 59 1312097 < BS <= 1613447 60 1613447 < BS <= 1984009 61 1984009 < BS <= 2439678 62 2439678 < BS <= 3000000 63 BS > 3000000


8. An integrated circuit that is built into a terminal device that transmits a signal to a base station apparatus through uplink, the integrated circuit causing the terminal device to perform a sequence of functions that comprises: a function of transmitting to the base station apparatus a first MAC control element which includes a first buffer size field indicating an amount of first data available for transmission within a first buffer for the uplink, and of transmitting to the base station apparatus a second MAC control element which includes a second buffer size field indicating an amount of second data available for transmission within a second buffer for a first link that is used for communication between the terminal device and a different terminal device, wherein, in a case where a first parameter that is indicated with a higher layer is not configured, a correspondence between a value that is used in the first buffer size field and the amount of the first data available for transmission within the first buffer is indicated by a first correspondence that is given with a first table, wherein, in the case where the first parameter is configured, the correspondence between the value that is used in the first buffer size field and the amount of the first data available for transmission within the first buffer is indicated by a second correspondence that is given with a second table different from the first table, and wherein a correspondence between a value that is used in the second buffer size field and an amount of second data available for transmission within the second buffer is indicated by the first correspondence.
 9. A wireless communication method that is used in a terminal device that transmits a signal to a base station apparatus through uplink, the wireless communication method comprising: transmitting to the base station apparatus a first MAC control element which includes a first buffer size field indicating an amount of first data available for transmission within a first buffer for the uplink, and transmitting to the base station apparatus a second MAC control element which includes a second buffer size field indicating an amount of second data available for transmission within a second buffer for a first link that is used for communication between the terminal device and a different terminal device, wherein, in a case where a first parameter that is indicated with a higher layer is not configured, a value that is used in the first buffer size field is indicated with a first table, wherein, in the case where the first parameter is configured, the value that is used in the first buffer size field is indicated with a second table different from the first table, and wherein a value that is used in the second buffer size field is indicated at all times with the first table.
 10. The wireless communication method according to claim 9, wherein each of the first table and the second table indicates a correspondence between a value of the buffer size and an index, and wherein an index in the second table indicates a value of an extended buffer size rather than a value of a buffer size to which an index in the first table corresponds.
 11. The wireless communication method according to claim 10, wherein the following table (11) is used as the first table, and the following table (12) is used as the second table. TABLE 11 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 10 2 10 < BS <= 12 3 12 < BS <= 14 4 14 < BS <= 17 5 17 < BS <= 19 6 19 < BS <= 22 7 22 < BS <= 26 8 26 < BS <= 31 9 31 < BS <= 36 10 36 < BS <= 42 11 42 < BS <= 49 12 49 < BS <= 57 13 57 < BS <= 67 14 67 < BS <= 78 15 78 < BS <= 91 16  91 < BS <= 107 17 107 < BS <= 125 18 125 < BS <= 146 19 146 < BS <= 171 20 171 < BS <= 200 21 200 < BS <= 234 22 234 < BS <= 274 23 274 < BS <= 321 24 321 < BS <= 376 25 376 < BS <= 440 26 440 < BS <= 515 27 515 < BS <= 603 28 603 < BS <= 706 29 706 < BS <= 826 30 826 < BS <= 967 31  967 < BS <= 1132 32 1132 < BS <= 1326 33 1326 < BS <= 1552 34 1552 < BS <= 1817 35 1817 < BS <= 2127 36 2127 < BS <= 2490 37 2490 < BS <= 2915 38 2915 < BS <= 3413 39 3413 < BS <= 3995 40 3995 < BS <= 4677 41 4677 < BS <= 5476 42 5476 < BS <= 6411 43 6411 < BS <= 7505 44 7505 < BS <= 8787 45  8787 < BS <= 10287 46 10287 < BS <= 12043 47 12043 < BS <= 14099 48 14099 < BS <= 16507 49 16507 < BS <= 19325 50 19325 < BS <= 22624 51 22624 < BS <= 26487 52 26487 < BS <= 31009 53 31009 < BS <= 36304 54 36304 < BS <= 42502 55 42502 < BS <= 49759 56 49759 < BS <= 58255 57 58255 < BS <= 68201 58 68201 < BS <= 79846 59 79846 < BS <= 93479 60  93479 < BS <= 109439 61 109439 < BS <= 128125 62 128125 < BS <= 150000 63 BS > 150000

TABLE 12 VALUE (BYTE) OF BUFFER INDEX SIZE (BS) 0 BS = 0 1  0 < BS <= 10 2 10 < BS <= 13 3 13 < BS <= 16 4 16 < BS <= 19 5 19 < BS <= 23 6 23 < BS <= 29 7 29 < BS <= 35 8 35 < BS <= 43 9 43 < BS <= 53 10 53 < BS <= 65 11 65 < BS <= 80 12 80 < BS <= 98 13  98 < BS <= 120 14 120 < BS <= 147 15 147 < BS <= 181 16 181 < BS <= 223 17 223 < BS <= 274 18 274 < BS <= 337 19 337 < BS <= 414 20 414 < BS <= 509 21 509 < BS <= 625 22 625 < BS <= 769 23 769 < BS <= 945 24  945 < BS <= 1162 25 1162 < BS <= 1429 26 1429 < BS <= 1757 27 1757 < BS <= 2161 28 2161 < BS <= 2657 29 2657 < BS <= 3267 30 3267 < BS <= 4017 31 4017 < BS <= 4940 32 4940 < BS <= 6074 33 6074 < BS <= 7469 34 7469 < BS <= 9185 35  9185 < BS <= 11294 36 11294 < BS <= 13888 37 13888 < BS <= 17077 38 17077 < BS <= 20999 39 20999 < BS <= 25822 40 25822 < BS <= 31752 41 31752 < BS <= 39045 42 39045 < BS <= 48012 43 48012 < BS <= 59039 44 59039 < BS <= 72598 45 72598 < BS <= 89272 46  89272 < BS <= 109774 47 109774 < BS <= 134986 48 134986 < BS <= 165989 49 165989 < BS <= 204111 50 204111 < BS <= 250990 51 250990 < BS <= 308634 52 308634 < BS <= 379519 53 379519 < BS <= 466683 54 466683 < BS <= 573866 55 573866 < BS <= 705666 56 705666 < BS <= 867737 57  867737 < BS <= 1067031 58 1067031 < BS <= 1312097 59 1312097 < BS <= 1613447 60 1613447 < BS <= 1984009 61 1984009 < BS <= 2439678 62 2439678 < BS <= 3000000 63 BS > 3000000


12. A wireless communication method that is used in a terminal device which transmits a signal to a base station apparatus through uplink, the wireless communication method comprising: transmitting to the base station apparatus a first MAC control element which includes a first buffer size field indicating an amount of first data available for transmission within a first buffer for the uplink, and transmitting to the base station apparatus a second MAC control element which includes a second buffer size field indicating an amount of second data available for transmission within a second buffer for a first link that is used for communication between the terminal device and a different terminal device, wherein, in a case where a first parameter that is indicated with a higher layer is not configured, a correspondence between a value that is used in the first buffer size field and the amount of the first data available for transmission within the first buffer is indicated by a first correspondence that is given with a first table, wherein, in the case where the first parameter is configured, the correspondence between the value that is used in the first buffer size field and the amount of the first data available for transmission within the first buffer is indicated by a second correspondence that is given with a second table different from the first table, and wherein a correspondence between a value that is used in the second buffer size field and an amount of second data available for transmission within the second buffer is indicated by the first correspondence. 